Answer:
yes each input (time in hours) has a unique output(cost)
Step-by-step explanation:
I did the test
Score = 6x+y
so 6x+y = xy
⇒ 6x = xy-y
⇒ 6x = y(x-1)
⇒ y = 6x/(x-1)
for x=0, y=0
x=1 , not possible
x=2, y = 12
x = 3, y = 9
x = 4, y = 8
x = 5, y = 7.5 (not possible)
x = 6 , y = 7.1 (not possible)
x = 7, y = 7
x = 8, y = 6.85 (not possible)
x = 9, y = 6.75 (not possible)...
Only five scores are possible.
Answer:
The correct answer is A.) 45 + 70x < 250.
y = mx + b
She started at 45 miles (+ 45).
She has to go at least 250 miles (< 250).
She is driving at a constant, unchanging speed of 70 mph (70x).
An easy way to do this is to plug in your answer choices in the correct variable places.
A - 1,5 so 3 (5) -2 = 13 // 8 (1) + 5 = 13
Therefore does 13 = 13? Yes
B. 3,9 so 3 (9) -2 = 25 // 8 (3) + 5 = 29
Therefore does 25 = 29? NO, so choice B is out
C.-4,9 so 3 (9) -2 = 25 // 8 (-4) + 5 = -27
Does 25 = -27? NO, so C is out
D. -2,3 so 3 (3 )-2 = 7 // 8 (-2) + 5 = -11
Does 7 = -11? NO, so D is out
YOUR ANSWER IS A
2/15+1/15=3/15 which isn't less than a half
2/15+8/30=2/15+4/15=6/15 which isn't less than a half
2/15+5/15=7/15 which isn't less than a half
and 2/15+8/15=10/15 which is greater than a half, and when cancelled down is 2/3 which is definitely greater than a half:)
