11*4/7-10*2/7+2*9/7 5a的2n次方-15a的2n+1次方用提取公因式法分解因式.
问题描述:
11*4/7-10*2/7+2*9/7 5a的2n次方-15a的2n+1次方
用提取公因式法分解因式.
答
11*4/7-10*2/7+2*9/7
=2/7(11*2-10+9)
=2*21/7
=6
5a的2n次方-15a的2n+1次方
=5a的2n次方-3(5a的2n+1次方)
=5a的2n次方-3(5a的2n次方)5a
=5a的2n次方-15a(5a的2n次方)
=5a的2n次方(1-15a)