To answer this you can use a guess and check strategy.
Start with 5 minutes using it (25% lost) and 10 minutes charging (20% gained).
Try 7 minutes using it (35% lost) and 14 minutes charging (28%).
Next, 9 minutes (45%) and 18 minutes(36%).
10 minutes (50%) and 20 minutes (40%). This is the difference.
She used it for 10 minutes and charged it for 20 minutes.
Answer:
AN = 16 units
Step-by-step explanation:
So we can use the fact that 
- Since this is an isosceles triangle, segments FO and FR are both equal to 7
Manipulating the equation above to solve for AN we have 
- Substituting in the known values we have

Answer:

Step-by-step explanation:
So we have the equation:

First, distribute the left side:

Add values on the left side:

Add 7 to both sides. The right side cancels:

Subtract 2x from both sides. The left side cancels:

Divide both sides by -6:

Therefore, x equals -3.
Hi I think it is 83,023,007