5-(x-6)=4(3-2x)
<=>5-x+6=12-8x
<=>5+6-12=-8x+x
<=>-1=-7x
<=>x=1/7
Vaat
2)(2x-5)^2-4x^2=-5(2x-7)-6x
<=>(2x-5)^2- (2x)^2=-5(2x-7)-6x
<=>(2x-5-2x)(2x-5+2x)=-10x+35-6x
<=>-5*(4x-5)=-16x+35
<=>-20x+25=-16x+35
<=>-20x+16x=35-25
<=>-4x=10
<=>x=-5/2
vậy............
3)(3-6x)^2-5x=6x(-6x+5)-10
<=>9-36x+36x^2-5x=-36x^2+30x-10
<=>-36^2x+36x^2-36x-30x-5x=-10-9
<=>-71x=-19
<=>x=19/71
Vậy....
