The simplest form of 21:28 is 3:4. you just divide both numbers by the greatest common factor.
Answer:
B C E
Step-by-step explanation:
Read the question
The answer is 30 because you put 21/x= 70/100
you cross multiply 100 and 21 you get 2100 and you divide it by 70 you should get 30 cause you take out one 0 from both numbers and end up with 210 divided by 7 then you get 30
The answer to the first question is 30.
The table is an exponential function, and the equation that represents this function is 
<h3>The equation of the table</h3>
The table is given as:
x F(x)
4 15
5 31
7 127
8 255
Rewrite the table as:
x F(x)
4 16 - 1
5 32 - 1
7 128 - 1
8 256 - 1
Express as a base of 2
x F(x)
4 2⁴ - 1
5 2⁵- 1
7 2⁷ - 1
8 2⁸ - 1
Notice that the function is 1 subtracted from 2 raised to the power of the input.
This is represented as:

Hence, the equation of the table is 
Read more about exponential functions at
brainly.com/question/9608962
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