Question

Stiind ca: A/b=3/7
Aflati:2a+3b/4b=?

Answer 1

Explicație pas cu pas:

a/b=3/7=k

a/3=b/7 ; a=3k ; b=7k

2a+3b/4b=?

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2a+3b/4b=(2*3k+3*7k)/4*7k=27k/28k=27/28

Answer 2

 

$\displaystyle\bf\\\frac{a}{b}=\frac{3}{4}\\\\\\\frac{2a+3b}{4b}=\\\\\\=\frac{2a}{4b}+\frac{3b}{4b}=\\\\\\=\frac{2}{4}\times\frac{a}{b}+\frac{3}{4}=\\\\\\=\frac{2}{4}\times\frac{3}{7}+\frac{3}{4}=\\\\\\=\frac{2\times3}{4\times7}+\frac{3}{4}=\\\\\\=\frac{6}{28}+\frac{^{7)}3}{~~4}=\\\\\\=\frac{6}{28}+\frac{21}{28}=\\\\\\=\frac{6+21}{28}=\\\\\\=\boxed{\bf\frac{27}{28}}$