Jason is saving up to buy a digital camera that costs $490. so far he saved $175. he would like to buy the camera 3 weeks from now. what is the equation used to represent how much he must save every week to have enough money to purchase the camera ?

Jason should save 105 per week for 3 weeks to have enough money to purchase the camera.

Given:
total cost = 490
amount saved = 175
time left to save = 3 weeks.

490 = 175 + 3x
490 - 175 = 3x
315 = 3x
315/3 = 3x/3
105 = x

to check:
490 = 175 + 3(105)
490 = 175 + 315
490 = 490