Question

afla suma b+c daca ab+ac+70=170 si a=25

Answer 1

ab+ac=170-70
ab+ac=100
a*(b+c)=100
25*(b+c)=100
b+c=100:25
b+c=4

Answer 2

Avem ab+ac+70=170, dar stim ca a=2=> 25b+25c+70=170=> dam factor comun pe 25=> 25(b+c)+70=170=> 25(b+c)=170-70=> 25(b+c)=100=>b+c=100/25=>b+c=4