Answer:
21a + 17b
Step-by-step explanation:
To simplify, we need to distribute the 9 to the terms inside of the parentheses that it is being multiplied by and 4 to the terms inside of the parentheses that it is being multiplied by like so:
9(a)+9(b)+4(3a)+4(2b)
9a+9b+12a+8b
Add like terms
21a + 17b
Answer:
102 ≤ heart rate ≤ 183.6
Step-by-step explanation:
... lower limit ≤ heart rate ≤ upper limit
Put 16 where "a" is and do the arithmetic.
... lower limit = 0.5(220 -16) = 102
... upper limit = 0.9(220 -16) = 183.6
Then the inequality is ...
... 102 ≤ heart rate ≤ 183.6
_____
<em>Comment on the problem</em>
There is nothing to "solve" here. One only needs to evaluate the limits.

Option ( A ) is the correct answer.
- Sum of all interior angle of a regular pentagon is 540°
- Number of edges in regular pentagon is 5.
- Number of vertices in regular pentagon is 5.