初2整式的乘除和因式分解的几道计算题,4(X+1)^2-(2X+5)(2x-5)3(Y-Z)^2-(2Y+Z)(-Z+2Y)[X(X^2Y^2-XY)-Y(X^2-x^3Y)]÷3X^2Y解方程;(X+7)(X+5)-(X+1)(X+5)=42解不等式;X(2X-5)>2X^2-3X-4(X+1)(X+3)+8X>(X+5)(X-5)-2

Question

初2整式的乘除和因式分解的几道计算题,
4(X+1)^2-(2X+5)(2x-5)3(Y-Z)^2-(2Y+Z)(-Z+2Y)[X(X^2Y^2-XY)-Y(X^2-x^3Y)]÷3X^2Y 解方程;(X+7)(X+5)-(X+1)(X+5)=42 解不等式; X(2X-5)>2X^2-3X-4 (X+1)(X+3)+8X>(X+5)(X-5)-2

Answer 1

4(X+1)^2-(2X+5)(2x-5)=4(X^2+2X+1)-4X^2+25=8X+263(Y-Z)^2-(2Y+Z)(-Z+2Y)=3(Y^2-2YZ+Z^2)-(4Y^2-Z^2)=4Z^2-6ZY-Y^2=[X(X^2Y^2-XY)-Y(X^2-x^3Y)]÷3X^2Y=(X^2Y(XY-1)-YX^2(1-XY)}/3X^2Y=(XY-1)(X^2Y+X^2Y)/3X^2Y=2/3*(XY-1)解方程;(X+7)(X+5)-(X+1)(X+5)=42(X+5)(X+7-X-1)=42(X+5)*6=42X+5=7X=2解不等式; X(2X-5)>2X^2-3X-42X^2-5X>2X^2-3X-4-2X>4X(X+5)(X-5)-2X^2+4X+3+8X>X^2-25-212X>-30X>-5/2X>-2.5