21.
So to solve for the value of a variable in an equation, you would need to isolate x on one side. The first thing you have to do is multiply 2 and (x + 7) together, which can be rewritten as 2(x) + 2(7). After multiplying, your equation would be:
, or A.
22.
So the rule with multiplying exponents with the same base is to add the exponents together, and the rule with dividing exponents with the same base is to subtract the exponents. Your equation will be simplified as such:

Now the rule with converting negative exponents into fractions is
. In this case, 4^-2 would turn into
, or C, which is your final answer.
Answer: -75
Step-by-step explanation:
What are we supposed to be basing this off of? is there no additional information?
N= x+15 where n = nina, x = the amount hiked together and the 15 is how much she already walked.