Question 342491
Let A,B and C be the numbers.
1.{{{A+B+C=75}}}
{{{B=5+4A}}}
{{{C=2A}}}
Substitute into eq. 1,
{{{A+5+4A+2A=75}}}
{{{7A+5=75}}}
{{{7A=70}}}
{{{highlight( A=10)}}}
.
.
.
{{{B=5+4(10)}}}
{{{highlight( B=45)}}}
.
.
.
{{{C=2(10)}}}
{{{highlight( C=20)}}}