Question

分解因式a²(x-y)-b²(x-y),1.25的4次方分之0.5的4次方×0.4的4次方×12.4

Answer 1

a²(x-y)-b²(x-y),

=(x-y)(a²-b²)

=(x-y)(a-b)(a+b)

1.25的4次方分之0.5的4次方×0.4的4次方×12.4的4次方

=0.5^4×0.4^4×12.4^4/1.25^4

=(0.5×0.4×12.4/1.25)^4

=(2.48/1.25)^4

=1.984^4

【这个题目可能有问题.】

(a+1)²-(1-a)(－a-1),其中a=3分之4

=(a+1)²+(1-a)(a+1)

=(a+1)(a+1+1-a)

=2(a+1)

=2×(4/3+1)

=2×7/3

=7/6