Question

ASAP Please help me

Answer 1

1. a) $ 25

b) $65

2) a) 246,000 followers

b) In 20 years

3a) $65

b) $85.25

Explanation:

1. A linear equation is modeled by
`y=mx+b`

where b is the one time fee you pay and m=$8 is how much you pay per hour.

y is the total cost and x is the number of hours.

Hence the equation becomes:
`y=8x+b`

Since Jill rented for 3 hours and paid $49, x=3 and y=49.

We substitute and solve for the one-time fee, b.

This implies that:

`49=8(3)+b`

49=24+b

b=49-24=25.

a) The fee is $25

b) We now write the equation in full to get:
`y=8x+25`

To find the cost for 5 hours we put x=5 into this equation and solve for y.

`y=8(5)+25`

y=40+25=$65

2a) We still use the equation y=mx+b.

b is the number of followers he started with.

This time m=-12,000 because he is losing followers at the rate of 12,000

The equation becomes: y=-12,000x+b

After 4 years he was down to 198,000.

This implies that, when x=4,y=198,000

We substitute to get:

`198,000=-12,000(4)+b`

`198,000=-48,000+b`

`b=198,000+48,000=246,000`

Hence he started with 246,000 customers

b) The equation now becomes
`y=-12,000x+246,000`

To find how many years he will have 6000 followers, we substitute y=6000 and solve for x.

`6000=-12,000x+246,000`

`6000-246,000=-12,000x`

`-240,000=-12,000x`

`x=(240,000)/(12,000)`

x=20.

3. We still use the equation: y=mx+b.

This time m=0.25 is the rate per mile.

This implies y=0.25x+b

Since Kyle drove 32 miles and spent $73, we have y=73 when x=32

We substitute these values and solve for x.

`73=0.25(32)+b`

`73=8+b`

`b=73-8`

`b=65`

Hence the one-time fee is $65

b) The equation now becomes:

`y=0.25x+65`

To find how much it will cost to drive 81 miles, we substitute x=81 and solve for y.

`y=0.25*81+65`

`y=20.25+65`

`y=85.25`

The cost for 81 miles is $85.25