Question

ma puteti ajuta, va rog?
daca a supra b egal cu 3 supra 7, atunci 3a+5b supra 7a+2b egal????

Answer 1

a supra b = 3 supra 7
=> 7a=3b => a=3b supra 7

3a+5b supra 7a+2b = 6b supra 7 + 5b (totul) SUPRA 21b supra 7 + 2b
=> (7 cu 7 se simplifica) 6b+5b supra 21b+2b = 11b supra 23b = 11 supra 23

Answer 2

[tex] \frac{a}{b}= \frac{3}{7} => 7a =3b => a= \frac{3b}{7} => \frac{3a+5b}{7a+2b} = \frac{ \frac{9b}{7} +5b}{ \frac{21b}{7} +2b} = \frac{44b}{7} * \frac{7}{35b} = \frac{44}{35} [/tex]