At Yvonne's auto dealing, car washes cost $5 for any time up to 10 minutes, plus $ .40 per minute after that. The managers at Yvonne's are trying to agree on a formula for calculating the cost c for a t-minute car wash. Sid thinks c = 0.4t + 5 is correct. Is he correct?

He is incorrect

Step-by-step explanation:

Here, given the charge at the auto dealing, we want to know if the formula the managers came up with is correct

The base fee is $5 for 10 minutes or less

Now for any extra minute after the tenth, $0.5 will be paid

So for a t-minute wash, the amount to be paid will be;

C = $5 + 0.4( t- 10) = 5 + 0.4t - 4 = 1 + 0.4t

If t < 10 , C = $5

If t > 10, C = 1 + 0.4t

Sid is incorrect

the first one, all those points on the line just make a strait line.