计算,(x+2)(y+3) (3mn-2)² 2(x²+5xy)-6(2xy-1/3x²) (X+2)(X-3)-(X+1))(X-2)
问题描述：
计算,(x+2)(y+3) (3mn-2)² 2(x²+5xy)-6(2xy-1/3x²) (X+2)(X-3)-(X+1))(X-2)
1.(x+2)(y+3) 2.(3mn-2)² 3.2(x²+5xy)-6(2xy-1/3x²) 4.(X+2)(X-3)-(X+1))(X-2) 5.(X+2Y)²-(X +Y)(X-Y),其中X=-2,Y=1/2 6.(3XY²).(-2XY) 7.(2A+1)²-(2A+1)(-1+2A)
答
1.xy+3x+2y+62.9m²n²—6mn+43.（2x²+10xy）—12xy+2x²=4x²—2xy4.（x²—3x+2x—6）—（x²—2x+x—2）=x²—x—6—x²+x—2=-85.x²+4xy+4y²—x²+y²=...