1.-5x=30 2.4\1x=2\1 3.3x+5=0 4.10-x+4x 5.6x-1=11 6.8y-3=5y+3 7.-7x+4=2x-4 8.x-2=3\1x+3\4

1.x=30/(-5)=-62.x=4/2=23.3x=-5x=-5/34.9-x+22.4x=1121.4x=2x=2/21.4 x=5/215.6x=11+1=12x=12/6=26.8y-5y=3+33y=6 y=27.-7x-2x=-4-4-9x=-8x=8/98.（同乘4x）4x^2-8x=12+3x4x^2-11x-12=o x=[-b±√(b^2-4ac)]/(2a)9....