Residents of the town of Windy Grove who are connected to the water supply are billed a fix amount each month plus a charge for each cubic foot of water used. A household using 1000 cubic feet was...

Residents of the town of Windy Grove who are connected to the water supply are billed a fix amount each month plus a charge for each cubic foot of water used. A household using 1000 cubic feet was filled $35, while one using 1600 cubic feet was billed $55. Write a formula T(w), for the monthly cost of a resident's water, where w is the cubic feet of water used.