中一數學題

a²+b² - a²b²
= a²(1-b²)+b² -1+1
= a²(1-b²)-(1-b²)+1
= (1-b²)(a²-1)+1
= (1-b)(1+b)(a+1)(a-1)+1

a2次方十b2次方一a2次方xb2次方
=a2次方十b2次方一ab4次方
=ab4次方一ab4次方
=0