Question

Numerele a si b sunt invers proportionale cu 12 , si respectiv 9 .
Cat la suta din b reprezinta a ?

Answer 1

{a;b}ip{12,9}=>a/12=b/9=k=>a=12k
                                                  b=9k
stim ca 12k=9k|:3=>4k=3k=>3b/4*100=75%b

Answer 2

[tex]\{a,b\} ip\{12,9\}\Rightarrow \frac{a}{\frac{1}{12}}=\frac{b}{\frac{1}{9}}=k\Rightarrow a=\frac{k}{12},b=\frac{k}{9}\\ a=\frac{x}{100}\cdot b\\ \frac{k}{12}=\frac{x}{100}\cdot \frac{k}{9}\\ \frac{1}{12}=\frac{x}{900}\\ 12x=900\\ x=75\%[/tex]