6x-7+9x+4 = 15x-3
-5x-3+2x-5 = -3x-8
4x²-3x+7+6x+5x²+2 = 9x²+3x+9
2(3x+5)+4(2x-3)=6x+10+8x-12=14x-2
-3(4x-2)-2(3x-4)=-12x+6-6x+8=-18x+14
2(5x-3)+4=10x-6+4=10x-2
2x(5x+3)-(8x²+2)=10x²+6x-8x²-2=2x²+6x-2
3(7x-5)-(2x+4)*2=21x-15-4x-8=17x-23
4x²-2-(9x²-3x+4)=4x²-2-9x²+3x-4=-5x²+3x-6
(5x-3)(2x+4)=10x²+20x-6x-12=10x²+14x-12
4x-2(3x-5)=4x-6x+10
(3x-2)(-6x+4)+10x²=-18x²+12x+12x-8+10x²=-8x²+24x-8
(4+5x)(2x-8)+2x²-3=8x-32+10x²-40x+2x²-3=12x²-32x-3
5
5x+(3-2x)(2+5x)+4 =5x+6+15x-4x-10x²+4=-10x²+16x+10