Question

Determinati x apartine lui R astfel incat 2(x+2)^2 - 11=61

Answer 1

2(x+2)^2-11=61 2(x^2+4)-11=61 2x^2+8-11=61 2x^2-3=61 2x^2=64 ×^2=32 ×=radical din 32

Answer 2

2(x+2)²-11=61
2(x+2)²=72
(x+2)²=36
|x+2|=6
i)x+2=6⇒x=4
ii)x+2=-6⇒x=-8
S:x∈{4,-8}