Question 945636


 
If the ratio of {{{a}}} to {{{b}}} is {{{4}}} to {{{5}}}, then we have 

{{{a/b=4/5 }}}=>solve for {{{a}}}

 {{{a=(4/5 )b}}}
{{{a=4b/5}}}

to find the value of the expression 

{{{(2a+3b)/(4b-3a)}}} substitute {{{4b/5}}} for {{{a}}}


={{{(2(4b/5)+3b)/(4b-3(4b/5))}}}


={{{(8b/5+3b)/(4b-12b/5)}}}


={{{(8b/5+15b/5)/(20b/5-12b/5)}}}


={{{(23cross(b)/cross(5))/(8cross(b)/cross(5))}}}


={{{23/8}}}