Question

what value of $n$ makes the equation true?
$(2x^{9}y^{n})(4x^{2}y^{10})=8x^{11}y^{20}$
$\bigcirc$ 1
$\bigcirc$ 2
$\bigcirc$ 10
$\bigcirc$ 30

Explanation:

Step1: Multiply coefficients

$2 \times 4 = 8$

Step2: Combine $x$-terms (add exponents)

$x^{9+2} = x^{11}$

Step3: Set up $y$-term equation

$y^{n+10} = y^{20}$

Step4: Solve for $n$

$n + 10 = 20 \implies n = 20 - 10 = 10$

Answer:

10 (Option C)