Question

Ar trebui foarte repede. Va rog foarte frumos...

Answer 1

cel mai simplu

aplici produs mezi=produs extremi

25a-10b=12a+4b

25a-12a=10b+4b

13a=14b | impartim prin b

13a/b=14 |im[partim prin 13

a/b=14/13

altfel

impartim toata relatia cu b

(5a/b-2)/(3a/b+1)=4/5

25a/b-10=12a/b+4

13* (a/b)=10+4=14

a/b=14/13

asta a fost mai complicata, am facut-o pt.verificare

Answer 2

$\\ \\ \dfrac {5a-2b}{3a+b}= \dfrac {4}{5} \iff 5(5a-2b) = 4(3a+b) \\ \\ \\ 5(5a-2b) = 4(3a+b) \iff \\ \\ 25a-10b =12a+4b \iff \\ \\ 25a-12a=10b+4b \iff \\ \\ 13a=14b \Rightarrow \boxed{\boxed{\dfrac{a}{b}=\dfrac{14}{13}}}$