Answer:

Step-by-step explanation:
As we seen that the reciprocal of the a/3(a/3) provides the result as a product number that gives the output as 1 .
Also we know that two fractions number gives output 1 if they are the reciprocal or multiplicative inverse from each other.
So, a/3(a/3

5x + 7x = 180 ⇒ properties of linear pair
12x = 80 ⇒ addition property (since (5 + 7)x = 12x)
x = 15 ⇒ Division property (since we divide both sides by 12)
16.4 is the answer. How to get the answer and others like it is like this. The first number after the decimal is the tenth place signaled by this .1 (For the examples I will always put the "1" where the value I'm trying to show) the hundredth place is here .21, and the thousandth is here .321 , hope this helps.
The answer is choice A, a 3.5% increase.
12/15 = 80%
13/17 = 76.47%
80% - 76.47% = 3.5%
The slope is 1/2 cuz its rise over run