Question

Решить уравнение

14y*1,8+21*(-0,3y)+21*1,8+14y*(-0,3y)=0

Answer 1

14y*1,8+21*(-0,3y)+21*1,8+14y*(-0,3y)=0

25,2y-6,3y+37,8-4,2y^2=0

18,9y+189/5-21/5y^2=0

189/10y+189/5-21/5y^2=0 |:10

189y+378-42y^2=0 |:21

-2y^2+9y+18=0 |*-1

2y^2-9y-18=0

2y^2+3y-12y-18=0

y(2y+3)-6(2y+3)=0

(2y+3)(y-6)=0

2y+3=0  2y=-3  y=-3/2  y1=-1,5

y-6=0  y2=6

Ответ: y1=-1,5 y2=6