Question

Chứng minh : (x+a). (x+b) =x²+(a+b).x+ab

Giúp mình với :(((

Answer 1

\(VP=x^2+\left(a+b\right)x+ab=x^2+\text{ax}+bx+ab=x\left(a+x\right)+b\left(a+x\right)=\left(x+a\right)\left(x+b\right)=VT\left(\text{đ}pcm\right)\)

Answer 2

Cm ve phai

=x^2+<a+b>*x+ab

=(x^2+x)[(a+b)+(a+b)

=x(x+1).ab