Question 950136
x, Jim's age
y, James age
-


Jim's age is seven less than two times James' age. 
{{{x=-7+2y}}}




Their combined age is forty-one.
{{{x+y=41}}}



SYSTEM OF EQUATIONS


{{{system(x=-7+2y,x+y=41)}}}


Substitute x into the age sum equation,
{{{(-7+2y)+y=41}}}
Simplify,
{{{2y-7+y=41}}}
{{{2y+y-7=41}}}
{{{3y-7=41}}}
{{{3y=41+7}}}
{{{3y=48}}}
{{{highlight(y=48/3=16)}}}


{{{x=2y-7}}}
{{{x=2*16-7}}}
{{{x=32-7}}}
{{{highlight(x=25)}}}



YOUR equation should still work, no matter which way James and Jims variables were assigned.  Your starting equation is good according to how you assigned x for James age.  You would get the y value for Jims age.