分解因式、解方程、应用题

4x的4次方-4x³+x²
=x^2(4x^2-4x+1)
=x^2(2x-1)^2

ab+a+b+1
=a(b+1)+b+1
=(a+1)(b+1)

(x-1)(x-2)-2(2-x)²
=(x-2)(x-1-2x+4)
=(x-2)(3-x)

解方程
(2a-3)²=(2a+1)(2a-1)-2
4a^2-12a+9=4a^2-3
12a=12
a=1
应用题

已知(a+b)²=7,(a-b)²=4,求a²+b²和ab的值
(a+b)^2=7
a^2+2ab+b^2=7
(a-b)^2=4
a^2-2ab+b^2=4

2(a^2+b^2)=11
a^2+b^2=11/2
4ab=3
ab=3/4