初一计算题(请写清楚步骤)1.(x+5)(x+5)-(x-2)(x-3)2.(2x-y)(2x-y)-4(x-y)(x+2y)3.(x+y+z)(x-y+z)

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 00:53:31
初一计算题(请写清楚步骤)1.(x+5)(x+5)-(x-2)(x-3)2.(2x-y)(2x-y)-4(x-y)(x+2y)3.(x+y+z)(x-y+z)

初一计算题(请写清楚步骤)1.(x+5)(x+5)-(x-2)(x-3)2.(2x-y)(2x-y)-4(x-y)(x+2y)3.(x+y+z)(x-y+z)
初一计算题(请写清楚步骤)
1.(x+5)(x+5)-(x-2)(x-3)
2.(2x-y)(2x-y)-4(x-y)(x+2y)
3.(x+y+z)(x-y+z)

初一计算题(请写清楚步骤)1.(x+5)(x+5)-(x-2)(x-3)2.(2x-y)(2x-y)-4(x-y)(x+2y)3.(x+y+z)(x-y+z)
1.(x+5)(x+5)-(x-2)(x-3)
=x^2+10x+25-(x^2-5x+6)
=x^2+10x+25-x^2+5x+6
=15x+31
2.(2x-y)(2x-y)-4(x-y)(x+2y)
=4x^2-4xy+y^2-4(x^2+xy-2y^2)
=4x^2-4xy+y^2-4x^2-4xy+8y^2
=9y^2-8xy
3.(x+y+z)(x-y+z)
=[(x+z)+y][(x+z)-y]
=(x+z)^2-y^2
=x^2+2xz+z^2-y^2

1.(x+5)(x+5)-(x-2)(x-3)
=x^2+10x+25-(x^2-5x+6)
=x^2+10x+25-x^2+5x+6
=15x+31
2.(2x-y)(2x-y)-4(x-y)(x+2y)
=4x^2-4xy+y^2-4(x^2+xy-2y^2)
=4x^2-4xy+y^2-4x^2-4xy+8y^2
=9y^2-8xy
3.(x+y+z)(x-y+z)
=[(x+z)+y][(x+z)-y]
=(x+z)^2-y^2
=x^2+2xz+z^2-y^2