Question

(-2x+1)(-2x-7)=0
Решить уравнение.

Answer 1

(-2x+1)(-2x-7)=0
4x^2+14x-2x-7=0
4x^2+12x-7=0
D=144-4*(-7)*4=256=16^2
x1=(-12+16)/8=0.5
x2=(-12-16)/8=3.5

Answer 2

-3.5