Question

Решите уравнения
1)69-(13-у)^2=-у^2
2)31-t^2=-(t-9)^2

Answer 1

$26y-100=0$
$26y=100$
$y= \frac{50}{13}$

$-18t+112=0$
$-18t=-112$
$t= \frac{56}{9}$