Question

preciso do calculo!!!!!!!!

Answer 1

$x+y=10 \\ x-y=6 \\ \\ x+y=10 \\ x=10-y \\ \\ x-y=6 \\ (10-y)-y=6 \\ 10-2y=6 \\ 10-6=2y \\ 4=2y \\ y=4/2 \\ y=2 \\ \\ x=10-y \\ x=10-2 \\ x=8$

A) Errada
$x^{2} + y^{2} \\ 8^{2} + 2^{2} \\ 64 + 4 \\ 68$

B) Correta
$x^{2} - y^{2} \\ 8^{2} - 2^{2} \\ 64 - 4 \\ 60$

C) Errada
$x^{2} + y^{2} \\ 8^{2} + 2^{2} \\ 64 + 4 \\ 68$

D) Errada
$x^{2} - y^{2} \\ 8^{2} - 2^{2} \\ 64 - 4 \\ 60$