Question 1150961
<pre>
{{{matrix(1,3,(5x-1)/8,""="",3)}}}

Multiply both sides by 8:

{{{matrix(1,3,8*((5x-1)/8),""="",8*(3))}}}

{{{matrix(1,3,cross(8)*((5x-1)/cross(8)),""="",24)}}}

{{{matrix(1,3,5x-1,""="",24)}}}

Add +1 to both sides:

{{{matrix(1,3,5x-1+1,""="",24+1)}}}

{{{matrix(1,3,5x-cross(1)+cross(1),""="",24+1)}}}

{{{matrix(1,3,5x,""="",25)}}}

Divide both sides by 5:

{{{matrix(1,3,(5x)/5,""="",25/5)}}}

{{{matrix(1,3,(cross(5)x)/cross(5),""="",5)}}}

{{{matrix(1,3,x,""="",5)}}}

Proved

Edwin</pre>