Question

Expand the following $(-2x+5y{)}^3$

• A. $8x^3-125y^3+60x^{2}y-150x{y}^2$
• B. $-8x^3+125y^3-60x^{2}y-150x{y}^2$
• C. $-8x^3-125y^3+60x^{2}y-150x{y}^2$
• D. $-8x^3+125y^3+60x^{2}y-150x{y}^2$

Answer 1

Answer: (D)

$-8x^3+125y^3+60x^{2}y-150x{y}^2$

$(-2x+5y{)}^3$
using the formula, $(a+b{)}^3=a^3+b^3+3ab(a+b)$
$=(-2x{)}^3+(5y{)}^3+3\times (-2x)\times \left(5y\right)(-2x+5y)$
$=-8x^3+125y^3+60x^{2}y-150x{y}^2$