Question

Simplify completely: the quantity 10 times x to the 6th power times y to the third power plus 20 times x to the third power times y to the 2nd power all over 5 times x to the third power times y

a.2x^9y64 + 4x^6y^3

b.2x^3y^2 + 4xy

c.2x^3y^2 + 4y^2

d.2x^3y^2 + 4y

Answer 1

Correct answer is D.

$\frac{10x^6y^3 + 20x^3y^2}{5x^3y} \\ \\ \text{common in the numerator is } \\ \\ 10x^3y^2 \\ \\ \text{so} \\ \\ \frac{10x^3y^2(x^3y + 2)}{5x^3y} \\ \\ \text{cancel common factors... } \\ \\ 2y(x^3y + 2) = 2x^3y^2 + 4y$