Answer:
A
Step-by-step explanation:
When you read the question it says that her average speed from the library to the gym is 15 mph less than her speed from her home to the library. So x - 15 is what describes that situation.
If it is A it cannot be anything else.
B is incorrect. x - 15 is not a time. It is a rate. It can be used to develop the amount of time, but by itself it is still A.
C is incorrect. Her average speed from her house to the library is x
D is incorrect. The distance is given as the same as from her home to the library as from the library to the gym. Both are 4
Answer: You need a grade of 78 on the final exam to earn a final grade average of at least 87 in each grading system.
Step-by-step explanation:
(85 + 90 + 95 + x)÷ 4 =87
Simplify:
(270 + x) ÷ 4 = 87
Rearrange:
(x + 270) ÷ 4 = 87
Multiply terms to Reduce:
4((x + 270) ÷ 4) = 4 * 87
Cancel Multiplied terms in Denominator:
x + 270 = 4 * 87
Multiply:
x + 270 = 348
Subtract 270 on both sides of the equation:
x + 270 - 270 = 348 - 270
Simplify:
x = 78
Answer:
the answer is A
Step-by-step explanation:
Answer:

Step-by-step explanation:
You could change the equation to this: 
*This is the exact same as 
You can continue to break this down until you get:

*This too = 
With this new equation, you can cancel out the common term: 
You come up with my answer.
<em>Hope this helps!!</em>