Question

daca a+2b+c=17 si 2a+3b+2c=23, atunci cu cat este egal 5a+6b+5c?

Answer 1

2a+3b+2c=23
 a+2b + c=17
___________  -
a+ b +c= 6
a+b+c+b=17
6+b=17
b=17-6
b=13

5a+6b+5c=?
5a+5b+5c=6x5=30
5(a+b+c)+b=
5x6+13=30+13=43
deci
5a+6b+5c=43