Question

（1）x^3+3x^2-12x+m有公因式x+3,则m=?（2）已知a+b=3,ab=二又二分之一,求代数式a^2b+2

Answer 1

1,x^3+3x^2-12x+m=x^2(x+3)-12x+m有公因式x+3

则-12x+m有公因式x+3,-12x+m=-(x+3)*12 m=-36

2.a^2b+2a^2b^2+ab^2=a^2b+ab^2+2a^2b^2=ab(a+b+2ab)=(5/2)*(3+2*5/2)=(5/2)*8=20

3.5^23-5^21=5^21(5^2-1)=5^21*24=5^20*120能被120整除

4.11111111-2222=11111111-1111-1111=11110000-1111=11108889