The small numbers in math shows that you have to mutiplies how much the power is. For Example, 5 with a power of 2 → 5² that's what it looks like.
The lnl is an absolute number which basically means it's positive regardless
So now its 7n-7=14
Simply add the 7 to the 14 to get it off the 7n side so you can simplify
Now it's 7n=21
Now just divide
21/7=3
3=N
That means 7 times N=21
A: x = 2.4
b: m = 9.6
c: c = 2 5/12
d: m = 3.6
e: c = 6.6
