Question

14+(х-7)²=78
Решите пожалуйста, уравнение!
Корни (-1;15)

Answer 1

$14+(x-7)^{2}=78\\\\(x-7)^{2}=78-14\\\\(x-7)^{2}=64\\\\\left[\begin{array}{ccc}x-7=-8\\x-7=8\end{array}\right\\\\\left[\begin{array}{ccc}x=-1\\x=15\end{array}\right\\\\Otvet:\boxed{-1;15}$

Answer 2

14+х2-14х+49=78
63+х2-14х=78
63+х2-14х-78=0
-15+х2-14х=0
х2-14х-15=0
х2+х-15х-15=0
х•(х+1)-15х-15=0
х•(х+1)-15(х+1)=0
(х+1)•(х-15)=0
х+1=0
х-15=0
х=-1
х=15