Let S = the original price of the sweater. Now, lets step through the problem...
The friend goes shopping with $35 and ends up left with $10.50. This means she spent 35 - 10.50 = 24.50 on the sweater after the sale and coupon.
Next, the sweater is on sale for 50%. This means we take S and take 50% of that. S*.50
Next, she uses a $5 off coupon. Thus, we want to subtract $5 from the price.
Lets combine this all together!
24.50 = S*.50 - 5
Solve for S.
24.50 = S*.50 - 5
29.50 = S*.50
$59 = S
Thus, the original price of the sweater was $59.
