Question

(2х+3)2=(-х-7)2 решить уравнение ​

Answer 1

4x+6=-2x-14
4x+2x=-14-6
6x=-20
x=-10/3

Answer 2

Ответ:

${(2x + 3)}^{2} = {( - x - 7)}^{2} \\ 4 {x}^{2} + 12x + 9 = {x}^{2} + 14x + 49 \\ 4x {}^{2} + 12x + 9 - {x}^{2} - 14x - 49 = 0 \\ 3 {x}^{2} - 2x - 40 = 0 \\ d = {b}^{2} - 4ac = 4 - 4 \times 3 \times ( - 40) = \sqrt{} 484 = 22 \\ x = \frac{2 - 22}{6} = \frac{20}{6} = \frac{10}{3} = 3 \frac{1}{3} \\ x = \frac{2 + 22}{6} = \frac{24}{6} = 4$