Giải thích các bước giải:
c, 2x²+3(x-1)(x+1)= 5x(x+1)
⇔2x²+3(x²-1)=5x²+5x
⇔2x²+3x²-3=5x²+5x
⇔2x²+3x²-5x²-5x=3
⇔-5x=3
⇔x=-3/5
Vậy x=-3/5
d, (8-5x)(x+2)+4(x-2)(x+1) +(x-2)(x+2)
=8x+16-5x²-10x+4x²-4x-8+x²-4
= -6x+4
e, 4(x-1)(x+5)-(x+2)(x+5)= 3(x-1)(x+2)
⇔4x²+20x-4x-20-x²-5x-2x-10=3x²+6x-3x-6
⇔4x²+20x-4x-x²-5x-2x-3x²-6x+3x= 20+10-6
⇔6x=24
⇔x=4