因式分解-25x^2-30xy-9y^2

6个回答

  • 1.-25x^2-30xy-9y^2

    =-(25x²+30xy+9y²)

    =-(5x+3y)²

    2.34^2+34*32+16^2

    =34²+2*34*16+16²

    =(34+16)²

    =50²

    =2500

    3.38.9^2-2*38.9*48.9+48.9^2

    =(38.9-48.9)²

    =(-10)²

    =100

    4.54.5^2-30*16.35+4.5^2

    =这个题目好像是错的