(1)3.66²-(2*1.33)²=3.66²-(2.66)²=(3.66+2.66)(3.66-2.66)=6.32*1=6.32
(2)202²+202*98*2+98²=(202+98)²=300²=90000
因式分解
(1)x(x-1)-3x+4=x²-4x+4=(x-2)²
(2)4-12(x-y)+9(x-y)平方=9(x-y)平方-12(x-y)+4=(x-y-2)²
(3)8a四次方b立方-8a立方b四次方+2a平方b五次方=2a²b³(4a²-4ab+b²)=2a²b³(2a-b)²
(4)(a平方+1）平方-4a平方=(a平方+1+2a)(a平方+1-2a)=(a+1)²(a-1)²