30(1,8-y)^2+20(y+1,8)(y-1,8)=50y^2+140,4

Question

30(1,8-y)^2+20(y+1,8)(y-1,8)=50y^2+140,4

Answer 1

30(1.8-y)^2+20(y-1.8)(1.8+y)=50y^2+140.4
30(3.24-3.6y+y²)+20(y²-3.24)=50y²+140.4
97.2-108y+30y²+20y²-64.8=50y²+140.4
50y²-108y+32.4=50y²+140.4
-108y=108
y=-1

Answer 2

Получается 30(3,24-3,6y+y²)+20(y²-1,8y+1,8y-3,24)=97,2-108y+30y²+20y²-36y+36y-64,8=50y²+108y+32,4
Кажется так

Comments

там ответ -1