Question

During a construction project, engineers used explosives to excavate 140 feet of tunnel into a mountain. But because of time constraints and environmental concerns, they brought in a tunnel boring machine (TBM) to excavate the rest of the tunnel. The data table lists some observations an engineer made about the length of the tunnel after the TBM was introduced.
Which equation represents the length of the completed tunnel based on the number of days since TBM was introduced?

y = 45x + 140

y = 405x + 140

y = 68.33x + 140

y = 25x + 140

Answer 1

@JackofallTradez

Answer 2

Do you have any ideas? If not, I can explain ^_^

Answer 3

no not at all

Answer 4

When x = 6, y = 410
When x = 15, y = 815, and so on...
The only equation that works is y = 45x + 140, because 6 * 45 = 270, and 270 + 140 = 410. Same with 15 * 45 = 675, and 675 + 140 = 815