Question

25(x-2y)平方-4(2y+x)平方

Answer 1

25(x-2y)平方-4(2y+x)平方
=[5(x-2y)]² - [2(x+2y)]²
= （5x-10y+2x+4y）（5x-10y-2x-4y）
=(7x-6y)(3x-14y)

秋风燕燕为您答题 O(∩_∩)O
有什么不明白可以对该题继续追问
如果满意，请及时选为满意答案，谢谢

Answer 2

25(x-2y)平方-4(2y+x)平方
=( 5x-10y + 4y+2x)( 5x-10y - 4y-2x)
= ( 7x - 6y) ( 3x - 14y)

Answer 3

25（x-2y）^2-4(2y+x)^2

=[5(x-2y)+2(2y+x)][5(x-2y)-2(2y+x)]
=(7x-6y)(3x-14y)
=21x^2-116x*y+84y^2

*是× ^2是平方

Answer 4

=[5(x-2y)]²-[2(x+2y)]²
=(5x-10y+2x+4y)(5x-10y-2x-4y)
=(7x-6y)(3x-14y)

追问

再问你个题呗，简便方法计算73×145²-105²×73

追答

=73×(145²-105²)
=73×(145+105)(145-105)
=73×250×40
=730000