Question

Решить уравнение:

(7х - 2)(7х + 0,4) = 0

Answer 1

(7х-2) х (7х+4/10) = 0
(7x-2) x (7x+2/5) = 0
7x - 2 = 0
7x + 2/5 = 0
x = 2/7
x = -2/35
x1 = -2/35
x2 = 2/7
Дробовые пиши в столбик / = -

Answer 2

(7х-2)(7х+0,4)=0

7х-2=0
7х=2
х=2:7
х(1)=2/7

7х+0,4=0
7х=-0,4
х=-0,4:7
х(2)=-2/35