Question

daca a/3=5/b si a,b apartine lui R ,calculati 2ab-28

Answer 1

Mezii cu extremii => a*b=15
a*b*2=30.
deci 2*a*b-28=30-28=2.

Answer 2

$\it \dfrac{a}{3} =\dfrac{5}{b} \Rightarrow ab=15|_{\cdot2} \Rightarrow 2ab=30|_{-28}\Rightarrow 2ab-28=2$