The cost of company 1: 10x+50
The cost of company 2: 8x+60
The cost will be the same at:

The answer is 5 hours
That would be D. The first two would be fight (I think) except they don't include turning the calculator on. C is just plain wrong. D has all the right keystrokes.
After moving all the terms to the right of the equation and solving you would get A = -36/49. Hope this helps!
Interest is 3.20 per 100
3.2 × 275/100
=3.2 × 2.75
answer A $8.80
The first, third, and fifth options, hope this helps