Answer:

Step-by-step explanation:
Using the rule of exponents
with n > m
=
, thus
=
=
= 
Answer: The average of the first two test scores is 97.
Step-by-step explanation: Given that Kristie has taken five tests in science class. The average of all five of Kristie's test scores is 94 and the average of her last three test scores is 92.
We are to find the average score of her first two tests.
Let a1, a2, a3, a4 and a5 be teh scores of Kristle in first , second, third, fourth and fifth tests respectively.
Then, according to the given information, we have

and

Subtracting equation (ii) from equation (i), we get

Thus, the average of the first two test scores is 97.
Answer:
d = 5
Step-by-step explanation:
We want to know what d would be when x = -1, so we can start off by plugging in -1 for x to get the following equation:
. On the left hand side, 2 negatives become a positive sign, so the -(-1) becomes a +1, and 8+1 would equal 9. On the right hand side, we just multiply 2 and -1 to get -2. So, the equation now looks like this:
. We know that
= 3, so we would get 3 = d-2. THen we would add 2 to both sides to get d = 5. Hope this helps!
Answer:
Total time taken by walking, running and cycling = 22 minutes.
Step-by-step explanation:
Let the speed of walking = x
As given,
The distance of walking = 1
Now,
As 
⇒ Time traveled by walking = 
Now,
Given that - He runs twice as fast as he walks
⇒Speed of running = 2x
Also given distance traveled by running = 1
Time traveled by running = 
Now,
Given that - he cycles one and a half times as fast as he runs.
⇒Speed of cycling =
(2x) = 3x
Also given distance traveled by cycling = 1
Time traveled by cycling = 
Now,
Total time traveled = Time traveled by walking + running + cycling
=
+
+ 
= 
If he cycled the three mile , then total time taken =
+
+
= x
Given,
He takes ten minutes longer than he would do if he cycled the three miles
⇒x + 10 = 
⇒
⇒
⇒x =
= 12
⇒x = 12
∴ we get
Total time traveled by walking + running + cycling =
min