Question

Cho a.b = -15 
Tính : a.(-b) ; (-a).b ; (-a) . (-b) 

Answer 1

\(a\cdot\left(-b\right)=15\)

\(\left(-a\right)\cdot b=15\)

\(\left(-a\right)\cdot\left(-b\right)=-15\)

Answer 2

\(a.b=15\\ khi\text{đ}\text{ó}:a.\left(-b\right)=-15\\ \left(-a\right).b=-15\\ \left(-a\right).\left(-b\right)=15\)

Answer 3

Ai giúp mk zới !!!

Answer 4