化简2(2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X)
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/30 01:38:26
![化简2(2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X)](/uploads/image/z/998377-25-7.jpg?t=%E5%8C%96%E7%AE%802%EF%BC%882X-7Y%29%287Y%2B2X%29%2BX%5E2-%28-4X%2B5Y%29%28-5Y-4X%29)
化简2(2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X)
化简2(2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X)
化简2(2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X)
2(2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X)
=2(4X^2-49Y^2)+X^2-(16X^2-25Y^2)
=8X^2-98Y^2+X^2-16X^2+25Y^2
=-7X^2-73Y^2
=2(14XY+4X-49Y^2-14XY)+X^2-(20XY+16X^2-25Y^2-20XY)
=28XY+8X-98Y^2-28XY+X^2-20XY-16X^2+25Y^2-20XY
=-40XY+8X-73Y^2-15X^2