Question

Решите уровнение
69-(13-у)$^{2}$=-у$^{2}$
31-t$^{2}$=-(t-9)$^{2}$

Answer 1

69 - (169 - 26 + y2) = -y2
69 - 169 + 26y - y2 = -y2
69 - 169 + 26y = 0
-100 + 26y = 0
26y = 100
y = 50/13