а) -2,8*(3х+7)-4,2=1,4
– 8.4x – 19.6 – 4.2 = 1.4
– 8,4x = 1,4 + 4,2 + 19,6
-8.4x = 25.2
x = -3
б) 2х=х*(х+1,5)
раскроем скобки
2x = x2+1.5x
-x2+0.5x = 0
-10x2+5x = 0
10x2-5x = 0
5x(2x – 1) = 0
x(2x – 1) = 0
x1 = 0
2x – 1 = 0
x2 = 1/2
а) -2,8*(3х+7)-4,2=1,4
– 8.4x – 19.6 – 4.2 = 1.4
– 8,4x = 1,4 + 4,2 + 19,6
-8.4x = 25.2
x = -3
б) 2х=х*(х+1,5)
раскроем скобки
2x = x2+1.5x
-x2+0.5x = 0
-10x2+5x = 0
10x2-5x = 0
5x(2x – 1) = 0
x(2x – 1) = 0
x1 = 0
2x – 1 = 0
x2 = 1/2