Всем . с уравнениями, . 1) -2x-7= -4x 2) x= -x-7 3) (-2x+1) ( -2x -7) =0 4) x2^2=4 5) 2x^2= 8x 6) x^2-9x+14=0

(-2x+1)(-2x-7)=0
4x^2+14x-2x-7=0
4x^2+12x-7=0
D=144-4*4*(-7)=144+122=256
d=16
x1=(-12+16)/8=4/8=1/2=0.5
x2=(-12-16)/8=-28/8=-7/2=-3.5