(5х+6)²=у
у²+5у-6=0
D=25+4*6=49 (+-7²)
у1=(-5-7)/2= - 6
у2=(-5+7)/2=1
(5x+6)²= -6
25x²+60x+36+6=0
25x²+60x+30=0
5x²+12x+6=0
D/4=(-6)² -5*6= 6= (≈ ±2.45)
x1=(-6+2.45)/5= - 0.71
x2=(-6-2.45)/5= - 1.69
(5x+6)²=1
25x²+60x+36-1=0
25x²+60x+35=0
5x²+12x+7=0
D/4=36-35=1
x3=(-6+1)/5= - 1
x4=(-6-1)/5= - 1.4