Question

If 5x - 2y = 7 and xy = 2, find the value of (5x + 2y)2.
​

Answer 1

$5x - 2y = 7 \: \: \: \: and \: \: \: \: xy = 2 \\ \\ \red{ \mathtt{squaring \:}} \\ \\ {(5x - 2y)}^{2} = {7}^{2} = > 49$