14x-14>7x+7
14x - 7x > 7 + 14
7x > 21
x > 21/7
x > 3
If the test gives a positive result for an infected person 98% of the time, that means that 2% of the time, it gives a negative result for an infected person, which would be a false negative.
If the test is 97% accurate for non-infected people, that means that it gives a negative result 97% of the time. So a positive result will be given 3% of the time for non-infected people, which is a false positive.
After the 15% discount, Maria pays 85% of the cost. That cost is the sum of the fixed cost and the variable (per visit) cost.
... (updated cost) = 0.85×($150 +$30×a)
... (updated cost) = 127.50 +25.50a . . . . in dollars
What? Can you attach a photo?
