Algebra Practice

Polynomials Practice Test

Review polynomial vocabulary, operations, evaluation, composition, division, zeros, and graph behavior.

Polynomials Practice Test

20 mixed polynomial questions with worked explanations and error analysis.

Instant feedback · Worked explanations
Polynomial mixed review

Read the structure before you calculate.

Polynomial questions can look unrelated because one asks for degree, another for a value, another for a remainder, and another about a graph. The unifying skill is method recognition: identify the polynomial structure first, then apply the rule that belongs to it. This guide connects vocabulary, operations, evaluation, composition, division, zeros, and graph behavior.

Anchor 01Like terms share exactly the same variable powers.
Anchor 02For nonzero factors, product degrees add.
Anchor 03Division and evaluation connect through the Remainder Theorem.
Anchor 04Degree and leading sign control broad graph behavior.

1. Vocabulary is the map legend

Write a polynomial in standard form, from highest exponent to lowest. That ordering exposes the degree and leading coefficient and makes later operations easier to organize.

The degree skyline

The degree of a nonzero polynomial is its greatest exponent after like terms have been combined.

7
5
3
2
TermA coefficient-variable expression separated by addition or subtraction.
CoefficientThe numerical multiplier of a variable term; its sign belongs to it.
DegreeThe greatest exponent with a nonzero coefficient.
Leading coefficientThe coefficient of the highest-degree term in standard form.
ConstantA term with no variable factor; its degree is zero.
Like termsTerms whose variable parts, including exponents, match exactly.
Keep degree and leading coefficient separate. In -4x^5+2x^2-9, the degree is 5 and the leading coefficient is -4.
Illustrative example
Rewrite 3-2x^4+7x-x^2 as -2x^4-x^2+7x+3. The degree is 4 and the leading coefficient is -2.

2. Operations run on different rails

Addition, subtraction, and multiplication all use exponents, but not in the same way. The key distinction is simple: addition combines like terms; multiplication combines factors.

Add / subtract
Match identical powers.

Distribute subtraction signs, align like powers, and combine coefficients only when the variable parts match.

Multiply monomials
Multiply coefficients; add exponents.

(3x^2)(-4x^5)=-12x^7 The exponent rule belongs to multiplication, not addition.

Multiply polynomials
Every term meets every term.

Distribute systematically, then combine like terms. The degree of a nonzero product equals the sum of factor degrees.

Degree check

Predict before expanding

A cubic times a quartic has degree seven. This is a fast structural check on an expanded answer.

deg(PQ)=deg(P)+deg(Q)
Sign check

Subtraction distributes -1

A minus sign outside parentheses changes every sign inside before like terms are combined.

A(x)-B(x)=A(x)+(-1)B(x)
Illustrative example
Simplify: (4x^3-2x+5)-(x^3+6x-3). Distribute the minus sign, then combine like terms to get 3x^3-8x+8.

3. Evaluation and composition are input systems

Evaluation replaces every occurrence of the variable with one input. Composition makes one function's output become another function's input. Parentheses matter because the entire input must replace each x-slot.

Direct evaluation

For P(a), substitute a everywhere, then use the order of operations.

P(a)

Expression input

If the input is multi-term or negative, substitute it as a grouped expression.

P(t-2)

Composition

For f(g(x)), replace every x in f by the complete expression g(x).

f(g(x))
Start with x
Apply g
Apply f
Illustrative example
If f(x)=x^2+1 and g(x)=3x-2, then f(g(x))=(3x-2)^2+1. Expand only if a simplified polynomial is required.

4. Division, remainders, and the shortcut

Polynomial division splits a dividend into divisor × quotient + remainder. When the divisor is linear, the Remainder Theorem can replace a full division if the question asks only for the remainder.

Remainder Theorem

Dividing by x - a? Evaluate at a.

If P(x) is divided by x-a, the remainder is P(a).

x-a
x=a
P(a)
Long divisionArrange descending powers and keep missing powers visible when needed.
Synthetic divisionEfficient for a divisor of the form x-a; use coefficients in order.
Remainder checkA remainder must have degree smaller than the divisor.
Illustrative example
For P(x)=2x^3-x+5 divided by x-2, compute P(2)=16-2+5=19. The remainder is 19.

5. Zeros connect four representations

A zero is an input that makes the polynomial equal to zero. The same fact can be written as an evaluation statement, a root, a factor, or—when the zero is real—an x-intercept.

EvaluationP(a)=0
Zero / roota is a zero of P.
Factorx-a is a factor.
Graph(a,0) is an x-intercept if a is real.
Factor test

Zero remainder matters

If P(a)=0, division by x-a has remainder zero, so x-a is a factor.

Multiplicity

Repeated zeros change graph contact

Repeated factors can make a graph cross an axis differently from a simple zero.

Degree bound

Not every zero is a visible intercept

A polynomial may have complex zeros, so the number of real x-intercepts can be smaller than its degree.

6. Degree and leading sign control the horizon

For very large positive or negative x, the leading term dominates. That makes degree parity and leading-coefficient sign the fastest clues for end behavior. Degree also limits the number of turns.

Even + positiveBoth ends rise.
Even + negativeBoth ends fall.
Odd + positiveLeft falls; right rises.
Odd + negativeLeft rises; right falls.
Turning-point limit: a degree-n polynomial has at most n-1 turning points. It can have fewer; n-1 is a maximum, not a guaranteed count.

7. Formula shelf

Memorize the relationship and the signal that tells you when to use it.

Like termsax^k+bx^k=(a+b)x^k

Use only when variable powers match exactly.

Monomial product(ax^m)(bx^n)=abx^(m+n)

Multiply coefficients; add exponents.

Product degreedeg(PQ)=deg(P)+deg(Q)

For nonzero polynomials.

Remainder Theoremrem. by x-a = P(a)

Use when only the remainder is needed.

Factor testP(a)=0 ⇔ x-a factor

Links evaluation, roots, and division.

Composition(f∘g)(x)=f(g(x))

The inner expression fills every x-slot.

Turning pointsmaximum=n-1

A structural ceiling, not an exact count.

Standard forma_nx^n+...+a_0

Descending powers reveal degree quickly.

8. Error analysis: detect the wrong rule

Many incorrect answers come from using a real algebra rule in the wrong context. Recognizing the source of an error is more useful than memorizing one correction.

Adding exponents during addition

x^2+x^3 does not become x^5. Exponents add when matching bases are multiplied.

Combining unlike terms

4x^2+3x cannot be combined because the variable powers differ.

Losing subtraction signs

In -(x^2-4x+1), every sign changes: -x^2+4x-1.

Coefficient vs. degree

The exponent gives degree; the number on the leading term is the leading coefficient.

Substitution without grouping

Negative and multi-term inputs should be placed in parentheses before powers are applied.

Treating n-1 as exact

The turning-point rule gives a maximum. A polynomial may have fewer turns.

9. Worked mini-set: identify the reason

These are illustrative teaching examples, not questions copied from the test.

Example A

Like-term control

(5x^4-3x^2+2)+(-2x^4+7x-6)
Result: 3x^4-3x^2+7x-4.

Example B

Product degree

(2x^3+1)(x^5-4x)
Degrees 3 and 5 give product degree 8.

Example C

Negative input

For P(x)=x^3-2x+4, P(-3)=-27+6+4=-17.

Example D

Remainder shortcut

Dividing by x+1=x-(-1) means evaluate P(-1).

Example E

Zero to factor

If P(4)=0, then x-4 is a factor and 4 is a real x-intercept.

Example F

End behavior

A leading term -3x^6 has even degree and negative lead, so both ends fall.

Final polynomial checklist

Before choosing an answer, run a short structural check. It catches many mistakes faster than repeating the whole calculation.

1
Standard form?Descending powers reveal degree and missing terms.
2
Adding or multiplying?Combine like terms in addition; add exponents in multiplication.
3
Subtraction distributed?A negative outside parentheses affects every term.
4
Input grouped?Use parentheses for negative values and composed expressions.
5
Remainder shortcut available?For x-a, the remainder is P(a).
6
Graph clue identified?Use degree parity, leading sign, and the n-1 turning-point ceiling.