Answer: Choice D 
Reason:
Exponential functions have the variable in the exponent.
Choice A is a polynomial, which means we can rule it out. Choice B is a log function, so we can rule it out also.
Choice C is a rational function because it is a ratio of two polynomials. This rules out choice C.
Choice D is the only function with the variable in the exponent. That is assuming you meant to say
instead of 
Answer: y=-1/5x+4
Step-by-step explanation: use the equation y=mx+b (x,y)->(5,3) 5 is an x value and 3 is a y value so you want to plug in these values into the equation. 3=-1/5(5)+b. We already know our slope so just plug it into m. Now multiply -1/5 and 5 which is -1. 3=-1+b you want to isolate b so you can find the intercept. Add one to both sides so it cancels out. 4=b we found our y-intercept so we can write the equation now. y=-1/5x+4
Answer:
56, 57, and 58.
Step-by-step explanation:
Answer:
3 metres
Step-by-step explanation:
If we draw this out, we'll see that there are actually two similar right triangles (see attachment), which means that we can set up a proportion.
The height of the lookout tower corresponds to the height of the wooden column, while the shadow of the lookout tower corresponds to the shadow of the wooden column. We can then write:
(height of lookout tower) / (shadow of tower) = (height of column) / (shadow of column)
16 / 12 = 4 / x , where x is the shadow / unknown we want to find
Cross-multiply:
16x = 48
x = 3
The answer is thus 3 metres.