Question 94603
Let the length of the first piece of rope be {{{L[1]}}} and the length of the second piece be {{{L[2]}}}. From the problem description, you can write:
{{{L[1] = 4x-1}}} and...
{{{L[2] = 3x+15}}}
But you are told that the lengths of the two pieces are equal, so...
{{{L[1] = L[2]}}} then...
{{{4x-1 = 3x+15}}} Simplify and solve for x. Subtract 3x from both sides.
{{{x-1 = 15}}} Add 1 to both sides.
{{{x = 16}}} This is the length of the person's forearm.
Graphically, we can show this result by graphing the two linear equations and noting the x-coordinate of the point of intersection.  This will give us the solution to the problem.
{{{graph(800,600,-5,20,-5,70,4x-1,3x+15)}}}