①.(2x+1)^2-(7-x)^2=0 ②.3x(x+1)=2x+2

问题描述:

①.(2x+1)^2-(7-x)^2=0 ②.3x(x+1)=2x+2

①.(2x+1)^2-(7-x)^2=0 [(2x+1)-(7-x)][(2x+1)+(7-x)]=0(2x+1-7+x)(2x+1+7-x)=0(3x-6)(x+8)=0(x-2)(x+8)=0x=2或x=-8②.3x(x+1)=2x+23x^2+3x=2x+23x^2+x-2=0(3x-2)(x+1)=0x=2/3或x=-1