Question

Ajutor va rog din suflet:
Se considera proportia $\frac{a}{b}$=$\frac{13}{4}$.Formand proportii derivate,determinati numerele a si b in fiecare dintre cazurile:
a.a - b=27
b.a+b=34
c.5a+2b+365

Answer 1

4a = 13b => a = 13b/4
a.
a-b = 17
13b/4 - b = 17 => 13b - 4b = 68 => => 9b = 68 => b = 68/9 ; a= 221/9
b.
a+b = 34
13b/4 + b = 34
13b + 4b = 136 => 17b = 136 => b=8 ; a= 26
c.
5a+2b = 365
5(13b/4) + 2b = 365
65b/4 + 2b = 365
65b + 8b = 1460 => 73b = 1460 => b = 20 ; a= 65