a)(x+2)(x+3)-5(x+1)=(x-1)2+6
x²+5x-5x-5=2x-2+6
x²-5=2x+4
x²-2x-9=0
b)3(x+5)-(2x-1)2-13=5(1-x)(1+x)+(x-3)2
3x+15-4x+2-13=5(1-x²)+2x-6
4-x=5-5x²+2x-6
4-x+1+5x²-2x=0
5x²-3x+5=0
c)(2x-3)(2x+3)-4x(x+1)=2(x+3)+3
4x²-9-4x²-4x=2x+6+3
-9-4x=2x+9
-9-4x-2x-9=0
-6x-18=0
-6x=18=>x=-3
