Answer:
9) The equation that represents our monthly bill is y=20+0.05m.
10) The equation that gives us the cost for the month is y=5+0.1m.
Explanation:
9) So if we are trying to find how much our monthly bill is where the monthly fee is 20 and we are charged $.05 per minute, then:
For 0 minutes, we spend 20 dollars in the month.
For 1 minute, we spend 20+.05=20.05 dollars in the month.
For 2 minutes, we spend 20+.05+0.05 or 20+2(.05)=20+.1=20.10 dollars in the month.
For m minutes, we spend 20+.05m.
The equation that represents our monthly bill is y=20+0.05m.
They gave us the y-intercept (the initial amount=20) and the rate (the slope=.05).
Remember: slope-intercept form is y=mx+b.
10) I'm going to shorten number 10.
They give us the rate=$.1/min and the initial cost=5 dollars.
The equation that gives us the cost for the month is y=5+0.1m.