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:
The identity property
Step-by-step explanation:
.......
9x +1= 0
9x/9 +1-1=0
X= 9-1
X= 8
Answer:
i don't know
Step-by-step explanation:
i am lower grade srry
Answer:
<h3>Total 20 boxes are there. </h3>
Step-by-step explanation:
Total number of shelves in a warehouse = 5 shelves.
Each shelve either can hold maximum 8 boxes with their lengths or can hold 4 boxes with their heights.
So, in that case only 4 boxes could be hold in each of 5 shelves because only 4 boxes could be fit with their heights.
Therefore, total number of boxes = 5 × 4 = 20 boxes .
<h3>Therefore, total 20 boxes are there. </h3>
