Question

Х2-(√7+1)х+√7=0 алгебра 8 сынып ​

Answer 1

$\displaystyle\bf\\x^{2} -(\sqrt{7} +1)x+\sqrt{7} =0\\\\D=(\sqrt{7} +1)^{2} -4\cdot \sqrt{7} =7+2\sqrt{7} +1-4\sqrt{7} =\\\\=7-2\sqrt{7} +1=(\sqrt{7} -1)^{2} \\\\\\x_{1} =\frac{\sqrt{7} +1+\sqrt{7} -1}{2} =\frac{2\sqrt{7} }{2} =\sqrt{7} \\\\\\x_{2} =\frac{\sqrt{7} +1-\sqrt{7} +1}{2} =\frac{2}{2} =1\\\\\\Otvet \ : \ \sqrt{7} \ \ ; \ \ 1$