Question

if x+2y=8 and xy=2 find the value of x2+4y2​

Answer 1

Step-by-step explanation:

x+2y=8

squaring on both sides

(x+2y)^2=8^2

x^2+4y^2+4xy=64

x^2+4y^2+4(2)=64

x^2+4y^2=64-8

x^2+4y^2=56