Answer:
Her second lap was <u>8%</u> better when compared to her first lap.
Step-by-step explanation:
Given:
Emily ran her first lap in 75 seconds she ran her second lap in 69 seconds.
Now, to find how much better was her second lap when compared to her first lap.
Emily ran her first lap in 75 seconds.
Emily ran her second lap in 69 seconds.
So, we get the difference in seconds:

<u><em>Thus, in her second lap she was 6 seconds better than first.</em></u>
Now, to get the percentage of her first lap better than second:



Therefore, her second lap was 8% better when compared to her first lap.
You just have to multiply each number by 180 and that's how many you have of each color respectively
Answer:
C. 
Step-by-step explanation:
Given the two equations:

To find:
The correct option when value of y is substituted to 2nd equation using the 1st equation.
Solution:
First of all, let us learn about the substitution method.
Substitution method is the method to provide solutions to two variables when we have two equations and two variables.
In substitution method, we find the value of one variable in terms of the other variable and put this value in the other equation.
Now, the other equation becomes only single variable and then we solve for the variable's value.
Here, we have two equations and value of one varible is:

Let us put value of y in 2nd equation:

So, the correct answer is option C. 
Step-by-step explanation:
There isn't any equation given, so there isn't anything to do here
A piece of wood 10 yards long
and
A piece of wood 5 feet long
He has two pieces of wood. How much does he have in all?
5+10 = 15
15 feet of wood