Step-by-step explanation: You have to substitute the inputs for x so you can get the outputs (y).
x = 2.5:
y = 124 - 1.7x
y = 124 - 1.7(2.5)
y = 124 - 4.25
y = 119.75
x = 5:
y = 124 - 1.7x
y = 124 - 1.7(5)
y = 124 - 8.5
y = 115.5
x = 8.3:
y = 124 - 1.7(8.3)
y = 124 - 14.11
y = 109.89
x = 10.8:
y = 124 - 1.7x
y = 124 - 1.7(10.8)
y = 124 - 18.36
y = 105.64
I'm really really sorry if I'm incorrect...