РЕШЕНИЕ
1)
4*2*x = 3*(15-x)
8*x = 45 - 3*x
11*x = 45
x = 45 :11 = 4 1/11 - ОТВЕТ
2)
3*3*x = 5*(12-x)
9*x = 60 - 5*x
14*x = 60
x = 60 : 14 = 4 2/7 - ОТВЕТ
3)
3*(3*x-1) = 2.5*(x-2)
9*x - 3 = 2.5*x - 5
6.5*x = - 2
x = 2 : 6.5 = - 4/13 - ОТВЕТ
4)
2,5*(2*x+5) = 4*(x-3)
5*x + 7.5 = 4*x - 12
x = - 19.5 - ОТВЕТ