Question

 Rezolvati ecuatia
a)$(x+1) ^{2} -(2x+1) ^{2} =(x-3) ^{2} -(2x-3) ^{2}$
b)$2(x-1) ^{3} -3(2x+5)=2(x+1) -4x(3x+2)^{3}$

Answer 1

a) x²+2x+1-4x²-4x-1=(x-3+2x-3)(x-3-2x+3)
-3x²-2x=-x(3x-6)
-3x²-2x=-3x²+6x
8x=0
x=0
b)
2(x-1)³-3(2x+5)=2(x+1)³-4x(3x+2)
2x³-6x²+6x-2-2x³-6x²-6x-2=6x+15-12x²-8x
-12x²-4+12x²=-2x+15
2x=19
x=19/2

Answer 2

a)x²+2x+1-(4x²+4x+1)=x²-6x+9-(4x²-12x+9)
x²+2x+1-4x²-4x-1=x²-6x+9-4x²+12x-9
-3x²-2x=-3x²+12x
-3x²+3x²-2x-12x=0
-14x=0
x=0

b)2(x-1)³-3(2x+5)=2(x+1)³-4x(3x+2)
2(x³-3x²+3x-1)-6x-15=2(x³+3x²+3x+1)-12x²-8x
2x³-6x²+6x-2-6x-15=2x³+6x²+6x+2-12x²-8x
2x³-6x²-17=2x³-6x²-2x+2
2x³-2x³-6x²+6x²+2x-17-2=0
2x-19=0     
2x=19
x=19/2