问题 解答题

把下列各式分解因式:

①a2-144b2

②πR2-πr2

③-x4+x2y2

答案

①a2-144b2

=a2-(12b)2

=(a+12b)(a-12b);

②πR2-πr2

=π(R2-r2),

=π(R+r)(R-r);

③-x4+x2y2

=-x2(x2-y2),

=-x2(x+y)(x-y).

单项选择题
单项选择题