Question

biểu thức D=(a+b)(a+1)(b+1)=.... nếu a+b=3,a.b=5 ?

giúp mik vs

Answer 1

`D=(a+b)(a+1)(b+1)`

`=3[ab+(a+b)+1]`

`=3(5+3+1)`

`=27`.

Answer 2

D=10 

 

(mk tính ra là như thế )

 

Answer 3

\(D=\left(a+b\right)\left(a+1\right)\left(b+1\right)\\ =3\left(a+1\right)\left(b+1\right)\\ =\left(3a+3\right)\left(b+1\right)\\ =3ab+3b+3a+3\\ =-15+3\left(a+b\right)+3\\ =-15+3.3+3\\ =-15+9+3\\ =-3\)