Question 1013841


 If {{{a:b =c:d =5:7}}}, find {{{(a+c):(b+d)}}}

 {{{a:b =5:7}}}

{{{7a=5b}}}

{{{a=5b/7}}}


 {{{c:d =5:7}}}

{{{7c=5d}}}

{{{c=5d/7}}}


=>
{{{(a+c):(b+d)}}}

={{{(5b/7+5d/7):(b+d)}}}

={{{((5b+5d)/7):(b+d)}}}

={{{(5(b+d))/7):(b+d)}}}

={{{(5(b+d))/7)/(b+d)}}}

={{{5(b+d)/7(b+d)}}}

={{{5/7}}}