Question

Решить уравнение 7x+x^2=0 6x^2+x-2=0

Answer 1

7x + x^2 = 0 
x *(7 + x) = 0 
x = 0 ;
x = - 7;

6x^2 + x - 2 = 0 
D = 1 + 4*12 = 49
x1 = ( - 1 + 7)/12 = 6/12 = 1/2;
x2 = ( - 1 - 7)/12 = - 8/12 = - 2/3

Answer 2

$7x+x^2=0\\\\x(7+x)=0\\\\x_1=0\\\\7+x=0,\; \; x_2=-7\\\\\\2)\; \; 6x^2+x-2=0\\\\D=1+4\cdot 6\cdot 2=49,\; \sqrt{D}=7\\\\x_1=\frac{-1-7}{12}=-\frac{8}{12}=-\frac{2}{3}\\\\x_2=\frac{-1+7}{12}=\frac{1}{2}$