math (ugh)
posted by brianna on .
Jermaine had dinner at his favorite restaurant. It the sales tax rate is 4% & the sales tax on the meal was $1.25, what was the total cost of the meal, including sales tax and a 15% tip

0.04x = 1.25
x = 1.25/0.04
x = 31.25
31.25 * 1.15 = ?? 
where did you get the 1.15, do u mean 1.25?

1.15 is the amount of the tip plus the meal.
You could also do it this way.
31.25 * 0.15 = 4.69
31.25 + 4.69 = ? 
TAX: $1.25
RATE: 0.04
TIP: 0.15
TOTAL = MEAL + TIP
MEAL = TAX/RATE = $1.25/0.04 = $31.25
TIP = MEAL*TIP PERCENTAGE = $31.25*0.15 = $4.69
TOTAL = MEAL + TIP = $31.25 + $4.69 = $35.94
(or, instead of adding the tip to the meal, you could multiply the meal by 1.15, which is like multiplying the meal by 0.15 and then adding that to the meal to get the tip + meal) 
37.19