Question

СРОЧНО!!! 30 БАЛЛОВ.
1/2 x² = -x +3
Решите и распишите!!!

Answer 1

$\displaystyle\bf\\\frac{1}{2} x^{2} =-x+3\\\\\\\frac{1}{2} x^{2} \cdot 2=-x\cdot 2+3\cdot 2\\\\\\x^{2} =-2x+6\\\\\\x^{2} +2x-6=0\\\\\\D=2^{2} -4\cdot(-6)=4+24=28=(2\sqrt{7} )^{2} \\\\\\x_{1} =\frac{-2-2\sqrt{7} }{2} =-1-\sqrt{7} \\\\\\x_{2} =\frac{-2+2\sqrt{7} }{2} =\sqrt{7} -1\\\\\\Otvet:-1-\sqrt{7} \ \ ; \ \ \sqrt{7} -1$