Question

Daca a / b = 3/8 aflati valoarea raportului 5a+7b/2b+3a

Answer 1

$\frac{a}{b}= \frac{3}{8} \Rightarrow a=3k~si~b=8k. \\ \\ \frac{5a+7b}{2b+3a}= \frac{5 \cdot 3k + 7 \cdot 8k}{2 \cdot 8k+3 \cdot 3k}= \frac{15k+56k}{16k+9k}= \frac{71k}{25k}= \frac{71}{25}.$

Answer 2

a/b=3/8⇒3b=8a⇒b=8a/3;
⇒5a+7·8a/3/2·8a/3+3a
⇒5a+56a/3/16a/3+3a
⇒5a+56a/3·1/16a/3+3a;
⇒⇒se reduce a cu a;
⇒5+56/3/16/3+3
⇒5+18,[6]/5,[3]+3
⇒23,[6]/8,[3]=2,83[9]⇒valoarea raportului;