$15 increase, but percentage is different. The $15 is equivalent to 33.33% of the new price. Thus, there would be a 33.33% increase in price. Hope i help
The general form of an equation is . Solving for (5+X)(5-X)=7 by multiplying the factors and subtratcting 7 on both sides gives the equation , so A = 1 B = 0 C = -18