Question

Multiply $(\frac{x}{2}-\frac{3y}{4})(\frac{x}{2}-\frac{3y}{4})$

• A. $\frac{x^2}{4}-\frac{3xy}{4}+\frac{9y^2}{16}$
• B. $\frac{x^2}{4}-\frac{3xy}{4}+\frac{9y^2}{10}$
• C. $\frac{x^2}{4}-\frac{3xy}{4}-\frac{9y^2}{16}$
• D. $\frac{x^2}{4}-\frac{3xy}{4}-\frac{9y^2}{10}$

Answer 1

The correct option is A $\frac{x^2}{4}-\frac{3xy}{4}+\frac{9y^2}{16}$

$(\frac{x}{2}-\frac{3y}{4})(\frac{x}{2}-\frac{3y}{4})$
Using,
$(a-b{)}^2=a^2-2ab+b2$
$={(\frac{x}{2}-\frac{3y}{4})}^2$
$=(\frac{x}{2}{)}^2-2(\frac{x}{2}\left)\right(\frac{3y}{4})+(\frac{3y}{4}{)}^2$
$=\frac{x^2}{4}-\frac{3xy}{4}+\frac{9y^2}{16}$