Answer:
21
Step-by-step explanation:
To evaluate, substitute w = 6 into the expression, that is
15 + w = 15 + 6 = 21
For direct variation, y = kx
8 = -4k
k = 8/-4 = -2
Therefore, required equation is y = -2x
when x = 7, y = -2(7) = -14
Let the walker’s speed be W, then the biker’s is W+1.5W=2.5W. Difference in speed is 1.5W. Distance=speed times time, so 12.5=1.5W×1.5=2.25W, and W=12.5/2.25=1250/225=50/9=5.56 mph. The biker’s speed is 2.5W=125/9=13.89 mph to 2 Dec places.
(Note: “1.5 times faster than a walker’s speed” could not reasonably mean the biker’s speed=1.5W because this would give W=16.67 mph, which is very fast for a runner, let alone a walker (!), and a biker’s speed of 25mph.)
Answer:
It's A.
Step-by-step explanation:
For every value of x there is one value of y - we can draw a vertical line through any value of x and it will pass through only one value of y.
Therefore it is a one-to-one function.