Answer:
A. Undefined will be your answer
Step-by-step explanation:
Let the speed for the first 12 mi be x mi/h, the speed for 18 mi was (x+4) mi/h
thus given that
time=distance/speed
the average time will be:
3=(12+18)/(x+x+4)
3=30/(2x+4)
solving for x we get
3(2x+4)=30
6x+6=30
6x=24
x=4 mi/hr
Answer: 12 mi/hr
Answer:
Raising something to a negative exponent is just taking the reciprocal of the amount.
Step-by-step explanation:
Let's assume that you wanted to know what 
is.
To find it, you would take the reciprocal of the x amount. So becomes 
.
This works because of the nature of exponents. Exponents represent the number of times you are multiplying a value by itself. So 
would be equal to a · a · a. To increase the exponent, you increase the number of times the value is multiplied by itself: To increase to 
, you would have to multiply a with two more times (a · a · a · a · a). To decrease the exponent, you must divide the value by itself. So to decrease to 
, you would have to divide by a 3 times.
If the exponent is 0, the value is equal to 1. But you can still decrease the exponent into negative numbers. You just divide 1 by a the desired amount of times: 
means that you are dividing 1 by a 3 times.
Hope this helps.
Answer:
21 girls.
Step-by-step explanation:
50% of 42 students are girls.
So 42/2 = 21.
Therefore 21 of the students are girls.
<em>Hope I helped</em>
