Question

if x+y=7 and xy =12 find x-y and xsquare-ysquare
please answer

Answer 1

$\begin{gathered}x + y = 7\\\\\text{Take square on both sides }\\\\(x+y)^2 = 7 ^2\\\\Expand\\\\x^2 + y^2 + 2xy = 49\\\\Substitute\ xy = 12\\\\x^2 + y^2 + 2(12) = 49\\\\x^2 + y^2 + 24 = 49\\\\x^2 + y^2 = 49 - 24\\\\x^2 + y^2 = 25\end{gathered}$