a-b=3 ab=2,求 a^2-b^2-6b+1的值

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 15:38:15
a-b=3 ab=2,求 a^2-b^2-6b+1的值

a-b=3 ab=2,求 a^2-b^2-6b+1的值
a-b=3 ab=2,求 a^2-b^2-6b+1的值

a-b=3 ab=2,求 a^2-b^2-6b+1的值
a²-b²-6b+1
=(a+b)(a-b)-6b+1
=3(a+b)-6b+1
=3a+3b-6b+1
=3a-3b+1
=3(a-b)+1
=9+1
=10

a-b=3, ab=2
a²-b²-6b+1=(a-b)(a+b)-6b+1
=3(a+b)-6b+1
=3a+3b-6b+1
...

全部展开

a-b=3, ab=2
a²-b²-6b+1=(a-b)(a+b)-6b+1
=3(a+b)-6b+1
=3a+3b-6b+1
=3a-3b+1
=3(a-b)+1
=3×3+1
=10

收起

a^2-b^2-6b+1
=(a-b)(a+b)-6b+1
=3(a+b)-6b+1
=3a+3b-6b+1
=3a-3b+1
=3(a-b)+1
=3×3+1
=10