Question

(5+х)^4-(5+x)^2-12=0
Срочно,пж!

Answer 1

(5+x)²=t
t²-t-12=0
D=1-4*1*12=49=7²
t1=1+7/2=4
t2=1-7/2=-3
__________
(5+x)²=4
25+10x+x²-4=0
x²+10x+21=0
D=100-4*1*21=16=4²
x1=-10+4/2=-3
x2=-10-4/2=-7
____________
(5+x)²=-3
нет решений

Ответ:-7;-3