Question

$8 - x = \sqrt{13x + 10}$

Answer 1

$(8 - x) {}^{2} = 13x + 10 \\ 64 - 16x + x {}^{2} = 13x + 10 \\ x {}^{2} - 16x - 13x + 64 - 10 = 0 \\ x {}^{2} - 29x + 54 = 0 \\ 29 {}^{2} \times 4 \times 54 = 841 - 216 = 625 \\ \sqrt{625} = 25 \\ x1. = \frac{29 + 25}{2} = \frac{54}{2} = 27 \\ x2 = \frac{29 - 25}{2} = \frac{4}{2} = 2$
подходит 2, потому что 8-2=√13*2+10
8-2=6
√36=6