Interest = (PRT)/100 = (1200×4×1)/100 = $48
Graphically I guess means graph it.
First graph goes to first problem. Second graph goes to second problem.
So to solve for y, subtract 108 from each side.
The equation becomes -y=126
Since you don't want y to be negative then divide each side by -1 this will flip all of the signs (positives become negative and vice versa) without changing the number.
So the equation is now y= -126