The answer is 3 8/9 because you turn it into a mixed number which is 5/3*7/3. Once you multiply you get 35/9. Since it is an improper fraction you turn it into a mixed number by dividing 35/9. In the end, you get 3 8/9 as your final answer.
Negative exponents work like this:

So, in order to evaluate a negative exponent, you simply have to invert the base, and then raise to the positive equivalent of the exponent.
As an example, here are the first three exercises:



You can work out the rest applying this logic.
Answer:
z = 8
Step-by-step explanation:
3/4 (z+4)=9
3/4z + 3 = 9
3/4z = 6
z = 8
Answer:
14) 21.136505024965 m
15) 43.076759215619 km
Step-by-step explanation:
14)
let h be the height of the lighthouse:
tan(41.3) = 18.7/h
Then
h = 18.7÷tan(41.5)
= 21.136505024965 m
………………………………………
15)
90-71.4 =18.6
Let s be the distance that the plane flew
towards the south:
tan(90 - 71.4) = s/128
Then
tan(18.6) = s/128
Then
s = tan(18.6)×128
= 43.076759215619 km
Answer: A. contains mirrors that reflect the object
Step-by-step explanation:
A periscope contains mirrors in it that are on opposite sides and are arranged in a 45° angle to each other. It works by light striking the first mirror which cause its to reflect it at a 45° angle to the next mirror.
Depending on the length of the periscope, this continues until the last mirror reflects the incoming light to the eyes of the person using the periscope thereby allowing them to see objects hidden behind or under a barrier.