Question

Daca $a*b-a*c=70$ si $b-c=5$, atunci numarul a este?
Ajutor!!!
Dau coroana !!!!

Answer 1

a*b-a*c=70
a(b-c)=70
b-c=5
a*5=70
a=70:5
a=14

Answer 2

$\displaystyle ab-ac=70;~b-c=5;~a=? \\ ab-ac=70 \Rightarrow a(b-c)=70 \Rightarrow 5a=70 \Rightarrow a= \frac{70}{5} \Rightarrow \boxed{a=14}$