2 х²+1.7 х=0

0.04x²-1=0

4x²-1.5x=0

-5x²+16x=0 решите 4 уравнения

1) 2x²+1,7x=0, x (2x+1,7) = 0

x1=0, x2=-17/20, x2=-0,85

2) 0,04x²-1=0, 4x²=100, x²=25

x1=5, x2=-5

3) 4x²-1,5x=0, x (4x-1,5) = 0

x1=0, x2=3/8, x2=0,375

4) - 5x²+16x=0, x (16-5x) = 0

x1=0, x2=16/5, x2=3,2

(a. b=0⇔a=0 ∨ b=0)