What this quiz covers

Grade 8 Exponents Quiz 2 draws its questions at random from 35 questions across these topics:


Worked examples

A few of the question types, with full solutions, so you know what to expect.

Coefficients. What is the coefficient in \(7x^3\)?

  1. \(7\)
  2. \(3\)
  3. \(x\)
  4. \(21\)

Answer: \(7\)

The coefficient is the number written in front of the variable.

In \(7x^3\): coefficient 7, base \(x\), exponent 3.

Tip: The exponent belongs to the \(x\) only. It never touches the 7.

Coefficients. What is the coefficient in \(-4a^2\)?

  1. \(-4\)
  2. \(4\)
  3. \(-2\)
  4. \(2\)

Answer: \(-4\)

The minus sign belongs to the coefficient.

Tip: Always carry the sign with the number. Dropping it is the most common slip in this topic.

Coefficients. What is the coefficient in \(y^5\)?

  1. \(1\)
  2. \(5\)
  3. \(0\)
  4. \(y\)

Answer: \(1\)

When no number is written, the coefficient is an invisible 1.

\(y^5 = 1y^5\)

Tip: Writing the 1 in lightly saves marks once you start collecting like terms.

Coefficients. What is the coefficient in \(-m^4\)?

  1. \(-1\)
  2. \(1\)
  3. \(-4\)
  4. \(4\)

Answer: \(-1\)

A lone minus sign means a coefficient of \(-1\).

\(-m^4 = -1m^4\)

Tip: Not \(-4\) - the 4 is the exponent, not the coefficient.

Multiplying terms. Simplify \(x^4 \times x^5\).

  1. \(x^9\)
  2. \(x^{20}\)
  3. \(x\)
  4. \(2x^9\)

Answer: \(x^9\)

Same base and we are multiplying, so add the exponents.

\(4 + 5 = 9\)

Tip: \(x^{20}\) comes from multiplying the exponents - that is the power-of-a-power rule.