Answer:
x = 12
Step-by-step explanation:
x - 5 = 84/x
x² - 5x = 84
x² - 5x - 84 = 0
x = (5 ±√(5² - 4(1)(-84))) / 2
x = (5 ± 19) / 2
x = -7 ignore
she is incorrect because if she was given a 20% discount the amount she would have to pay is 38.4
48 x .2 = 9.6
48 - 9.6 = 38.4 not 40
a. x=3
