Z²+3z+2z+6-z²-z=4z+6=4×(-6,5)+6=-20
c²-10c-5c+50+3c²+15c=4c²+50=4×(3,5)²+50=99
2n²-3n+2n-3+3n²+n-3n-1=5n²-3n-4
2x²-3yx-2yx+3y²-6x²-3yx+2yx+y²=-4x²-6yx+4y²=2y²-3yx-2x²
4a²+6a+6a+9-4a²+2a-2a+1=12a+10=6a+5
3cd+9c²-d²-3cd+4c²-16cd-dc+4d²=13c²-17cd+3d²
x²-3x-2x+6-x²-x=0
-6x=-6
x=1
x²+6x+4x+24-x²-30=0
10x-6=0
10x=6
x=0,6
x²+x-5x-5-x-x²-5=0
-5x-10=0
-5x=10
x=-2
x²-3x-x+3=x²-4x-2x+8
x²-4x+3-x²+6x-8=0
2x-5=0
2x=5
x=2,5