Sagot :
[tex]7x+5x=48\\\\
12x=48\ \ \ \ | divide\ by\ 12\\\\
x=4\\\\
7x=7*4=28\\
5x=5*4=20\\\\
48\ in\ ratio\ 7:5\ is\ 28:20.[/tex]
[tex]7+5=12\\\\48:12=4\\\\7\cdot4=28\ \ \ \ and\ \ \ \ 5\cdot4=20\\\\ \frac{\big{28}}{\big{20}} =\frac{\big{7}}{\big{5}} [/tex]