Question

REZOLVATI IN R ECUATIILE
a) 3(x-2)la puterea a 2 =2x+4
b)(x+2) la puteria a 2=x(3x+2)
c)(3x+4)la puterea a 2-(x-5) la puteria a 2 =-9

Answer 1

Răspuns:

a)

$3(x - 2)^{2} = 2x + 4 \\ 3 {x}^{2} - 12x + 12 - 2x - 4 = 0 \\ 3 {x}^{2} - 14x + 8 = 0 \\ delta = 196 - 4 \times 3 \times 8 \\ delta = 196 - 96 \\ delta = 100 = > \sqrt{delta} = 10 \\ x1 = \frac{14 - 10}{6} = \frac{2}{3} \\ x2 = \frac{14 + 10}{6} = 4$

b)

${x}^{2} + 4x + 4 = 3 {x}^{2} + 2x \\ 2 {x}^{2} - 2x - 4 = 0 \\ {x}^{2} - x - 2 = 0 \\ (x + 1)(x - 2) = 0 \\ = > x1 = - 1 \\ x2 = 2$