Question

Daca a supra b = 3 supra 7,atunci 3a+5b supra 7a+2b=  ??????

Answer 1

a/b=3/7
a/3=b/7=k
a=3k
b=7k
inlocuim in relatia care se cere a fi calculata
$\frac{3x3k+5x7k}{7x3k+2x7k} = \frac{9k+35k}{21k+14k} = \frac{441}{35}$

Answer 2

a/b = 3/7 
3a+5b/ 7a +2b = ? 
7a=3b ⇒ a= 3b/7 
3·3b/7+5b totul supra 7·3b+2b = 9b+35b/7 totul supra 21b +14b /7= 44b/7· 7/35 = 44b / 35b= 44/35