（-2x^2y^3)^2 (2a+3b)(2a-b) 5x^2(x+1)(x-1) (2x+y-1)^2 59.8*60.2 198^2（-2x^2y^3)^2 (2a+3b)(2a-b) 5x^2(x+1)(x-1)(2x+y-1)^259.8*60.2 198^2
问题描述：
（-2x^2y^3)^2 (2a+3b)(2a-b) 5x^2(x+1)(x-1) (2x+y-1)^2 59.8*60.2 198^2
（-2x^2y^3)^2
(2a+3b)(2a-b)
5x^2(x+1)(x-1)
(2x+y-1)^2
59.8*60.2
198^2
答
（-2x^2y^3)^2=2x^4y^6
(2a+3b)(2a-b)=(2a+b+2b)(2a-b)=2a^2+4ab-3b^2
5x^2(x+1)(x-1)=5x^2(x^2-1)=5x^4-5X^2
(2x+y-1)^2
59.8*60.2=(60-0.2)(60+0.2)=60^2-0.2^2
198^2=(200-2)^2=40000-800+4
答
1.（--2x^2y^3)^2=4x^4y^6.
2.（2a+3b)(2a--b)=4a^2--2ab+6ab--3b^2
=4a^2+4ab--3b^2.
3.5x^2(x+1)(x--1)=5x^2(x^2--1)
=5x^4--5x^2.
4.（2x+y--1)^2=(2x+y)^2--2(2x+y)+1
=4x^2+4xy+y^2--4x--2y+1.
5.59.8*60.2=(60--0.2)(60+0.2)
=60^2--(0.2)^2
=3600--0.04
=3599.96.
6.198^2=(200--2)^2
=200^2--2*200*2+2^2
=40000--800+4
=39204.