SOLUTION: Please help my solve this. It was in the form of a word problem and this is what I got it to. Now I am clueless on what to do. {{{d+e-f=5}}} {{{e=f+d+7}}} {{{f=2e-11}}} Th

You can put this solution on YOUR website!
To make it a bit easier, I'd rewrite it so every line is in the same form like:
Eq1:
Eq2:
Eq3:
Now in this form we can see that we can use combination and add Eq1 & Eq2 to write an equation only in terms of E&F:

Now that we have two equations of only two variables (this one & Eq3) we can solve for e & f. Adding this new equation to Eq 3 we get:


Putting this back into Eq 3 we get:




Now we know e & f, so we can use any equation (in this example Eq 1.) to find d:



Double checks:
Eq1:=check.
Eq2:=check.
Eq3:=check.