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.
About 10 songs because if you add up all ten numbers of all the songs then you divide, then you divide again you will get 10 songs
Answer:

Step-by-step explanation:

Answer:
3/4.
Step-by-step explanation:
There are 3 non leap years in every 4 year period so it s 3/4.
Answer:
r = 5
Step-by-step explanation: