Answer:
When you have 2 unknowns, you need 2 equations to solve for them.
Step-by-step explanation:
105 text messages
7.70 divied by 154 = 0.05
0.05 per text massage
5.25 divided by 0.05 = 105
to check work:
105 times 0.05 = 5.25
7.85 inches
8 hours and 31 minutes per day
