Question

sendo A=x-3 B=x-2 C=x+1 D=x+4 calcule AB+c BD+c A+CD ABC

Answer 1

x-3.x-2+x+1.x-2.x+4+x+1.x-3+x+1.x+4.x-3.x-2.x+1
x-3x-2+x+x-2x+4+x-3+x+x+4x-3x-2x+1
10x-10x+5-5   (corta 10x com -10x e 5x com -5)
0