I do not understand how to do this problem:
4e=5+2f
6f=9-4e
Could someone please explain to me how to solve this problem?
$\displaystyle 4e=5+2f \implies 4e-2f=5$
$\displaystyle 6f = 9-4e \implies 4e+6f=9$
so you have these two equations with two unknowns. You can easily find e and f
OR,
4e=5+2f and
6f = 9-4e. therefore, 4e = 9 -6f
so you can write
5+2f = 9-6f.
This will give you the value of f, after which you can find out e.