Answer: C. 

Step-by-step explanation:
If 't' represents the number of hours Joanne tutors and 'r' represents the number of hours she works as a receptionist.
Then the total hours she can work=t+r
Since she can work up to 25 hours.
Thus 
If she earns $25 per hour by tuition and $ 12 per hour by working as a receptionist .
Then her total earning =$
Since she must earn $200.
Then
.
Therefore, the required system of inequality will be


Answer:
x = 72 / 85
Step-by-step explanation:
x -6/7=-x/84
x + x/84 = 6/7
84/84x + 1/84x = (12*6) / (12*7)
85/84x = ( 72 ) / ( 84 )
85/84x = 72 / 84
Multiply left and right from the = sign by 84/85 and you do that so you get a division ON THE LEFT SIDE that equals as 1... See how it works:
84/85 * { 85/84 } * x = 84/85 * { ( 72 ) / ( 84 ) }
{ (84 * 85) / ( 85 * 84) } * x = ( 84 * 72 ) / ( 85 * 84 )
(7140) / ( 7140) * x =. ( 6048 ) / ( 7140)
x = 6048 / 7140
x = 72 / 85
For this case we must find the product of the following expression:

We combine using the product rule for radicals:
![\sqrt [n] {a} * \sqrt [n] {b} = \sqrt [n] {ab}](https://tex.z-dn.net/?f=%5Csqrt%20%5Bn%5D%20%7Ba%7D%20%2A%20%5Csqrt%20%5Bn%5D%20%7Bb%7D%20%3D%20%5Csqrt%20%5Bn%5D%20%7Bab%7D)
So, we have:

We rewrite the 216 as

By definition of properties of powers and roots we have:
![\sqrt [n] {a ^ n} = a ^ {\frac {n} {n}} = a](https://tex.z-dn.net/?f=%5Csqrt%20%5Bn%5D%20%7Ba%20%5E%20n%7D%20%3D%20a%20%5E%20%7B%5Cfrac%20%7Bn%7D%20%7Bn%7D%7D%20%3D%20a)
Then, the expression is:

Answer:
Option D
Answer:
i think its A but not %100
Step-by-step explanation: