please help im stuck

Question

a tank is filling with water from a natural spring. two days ago the water was ten feet deep, and yesterday the water was 12 feet deep.assume that the water depth continues to rise at this same rate after today. create an expression for this problem.

Answer 1

Let x = number of days since the depth was 10 feet

      y = depth of water on day x

 

Since the depth is increasing at a constant rate, the relationship between x and y is linear.

 

So, (0, 10) and (2, 12) are points on a line

 

slope of the line = (12 - 10)/(2-0) = 1

 

The equation of a line can be written as y = mx + b, where m is the slope and b is the y-intercept.  

 

We have:  y = 1x + b

 

Since (0, 10) is a point on the line, 10 = 1(0) = b.  So, b = 10.

 

Equation of line :  y = x + 10

Answer 2

It's essentially asking you to describe what's happening in one (mathematical) sentence. 

 

In two days, the water has risen 2 feet; in other words, in those two days, the water was rising at a rate of 1 foot per day. So for every day after today, the water level will keep rising 1ft/day.

 

Let L = water level, and t = number of days into the future (number of days after "today")

 

Thus L = t + 12.