（x+2）的四次方+y-1的绝对值=0（x+2）的四次方=0,y-1的绝对值=0x=-2y=15xy-【4x²y-（-3xy²+2x²+2x²y）】=5xy-【4x²y+3xy²+2x²+2x²y】=5xy-【4x²y+2x²y+3xy²...