Q:  Solve for n:  -700/n – (-5)(4) +1 = 121

A:  Let’s first do some house keeping and multiply / combine numbers where we can:

-700/n – (-5)(4) +1 = 121

-700/n – (-20) +1 = 121

-700/n +20 +1 = 121

-700/n + 21 = 121

Now, subtract 21 from both sides:

-700/n = 100

Multiply both sides by n:

n*(-700/n) = 100 * n

-700*n/n = 100n

Notice the n’s on the left side cancel each other out to get:

-700 = 100n

Divide both sides by 100:

-700/100 = n

-7 = n