Question

if xy = 9 and x-y =7, the value of x^2+y^2 is equal to

Answer 1

hello

(x - y)^2 = x^2 + y^2 - 2 xy

(7)^2 = x^2 + y^2 - 2 * 9

49 = x^2 + y^2 - 18

49 + 18 = x^2 + y^2

67 = x ^2 + y^2

hope it helps...

plz. mark as brainly...

Answer 2

$\begin{gathered}x-y = 7\\ \\ \Rightarrow (x-y)^2 = 7^2\\ \\ \Rightarrow x^2+y^2-2xy=49 \\ \\ \Rightarrow x^2+y^2-2 \times 9=49 \\ \\ \Rightarrow x^2+y^2-18=49 \\ \\ \Rightarrow x^2+y^2= 49+18\\ \\ \Rightarrow x^2+y^2 = 67\end{gathered}$