Question

Multimea solutiilor ecuatiei (x-2)²-7=2 este...?

Answer 1

(x-2)²-7=2
(x-2)²=2+7
(x-2)²=9
x-2=√9
x-2=+/-3
x-2=3  x=5
x-2=-3  x=-1
x∈{-1,5}

Answer 2

$x^{2} -4x+4-7-2=0 \\ x^{2} -4x-5=0 \\ delta = b^{2}-4ac=16+20=36 \\ x_{1} = \frac{-b- \sqrt{delta}}{2a}= \frac{4-6}{2}= \frac{-2}{2}=-1 \\ x_{2}= \frac{-b+ \sqrt{delta} }{2a}= \frac{4+6}{2}= \frac{10}{2}=5$
S={-1, 5}