Question

which expression is equivalent to: $7x^{4}\cdot4y^{-2}$
$\bigcirc$ $11x^{4}y^{2}$
$\bigcirc$ $28x^{2}$
$\bigcirc$ $\frac{28x^{4}}{y^{2}}$
$\bigcirc$ $\frac{11x^{4}}{y^{2}}$

Explanation:

Step1: Multiply the coefficients

$7 \times 4 = 28$

Step2: Rewrite negative exponent

$y^{-2} = \frac{1}{y^2}$

Step3: Combine all terms

$28 \times x^4 \times \frac{1}{y^2} = \frac{28x^4}{y^2}$

Answer:

$\frac{28x^4}{y^2}$