因式分解-25x^2-30xy-9y^21.-25x^2-30xy-9y^22.34^2+34*32+16^23.38.9^2-2_数学解答

因式分解-25x^2-30xy-9y^2
1.-25x^2-30xy-9y^2
2.34^2+34*32+16^2
3.38.9^2-2*38.9+48.9^2
4.54.5^2-30*16.35+4.5^2

人气：475 ℃　时间：2019-10-29 10:42:34

解答

1.-25x^2-30xy-9y^2=-(25x²+30xy+9y²)=-(5x+3y)²2.34^2+34*32+16^2=34²+2*34*16+16²=(34+16)²=50²=25003.38.9^2-2*38.9*48.9+48.9^2=(38.9-48.9)²=(-10)²=1004.54.5^2...