Ronny is selling coffee mugs for $3.50. So far, he has earned $245.00. Ronny needs to earn more than $315 in order to meet his sales goal. How many coffee mugs, x, does Ronny need to sell in order to reach his sales goal?

Y = 3.50x

245 = 3.50x

x = 245/3.5

x = 70 coffee mugs

315 = 3.50x

x = 315/3.5

x = 90 coffee mugs

Ronny needs to sell 90 coffee mugs to reach his sales goal. However, he already sold 70 coffee mugs, so he needs to sell an additional 20 coffee mugs to reach 90 coffee mugs and reach his $315 sales goal.