Question

Given $3x-2y=5$. Find the value of $2x^2-5xy(x+y)$; when $x=-5$

• A. $3700$
• B. $-3700$
• C. $3800$
• D. $-3800$

Answer 1

The correct option is C $3800$

Given, $3x-2y=5$ and $x=-5$
put $x=-5$ in $3x-2y=5$
$\Rightarrow 3(-5)-2y=5$
$\Rightarrow -2y=20$
$\Rightarrow y=-10$
Value of $2x^2-5xy(x+y)$ at $x=-5$ and $y=-10$ is
$2(-5{)}^2-5(-5\left)\right(-10\left)\right(-5-10)$
$=50-250(-15)$
$=50+3750=3800$