A = 4(x−5)−x2(x+1)−x3(x−3)−(x−4+x2)
A = 4x−20−x3−x2−x4+3x3−x+4−x2
A = −x3−3x3−x2+x2−x4+4x−x−20+4
A = −4x3−x4+4x−16
B = −3(x2−x+1)−2(4−x2)−6(x+1)−x4−x3
B = −3x2+3x−3−8+2x2−6x−6−x4−x3
B = −x4−x3−3x2−2x2+3x−6x−3−8−6
B = −x4−x3−5x2−3x−17
C = −(x4+3x2−2)−x2(5−x)+3(x−1)
C = −x4−3x2+2−5x2+x3+3x−3
C = −x4+x3−3x2+5x2+3x+2−3
C = −x4+x3−2x2+3x−1
#Yiin
