equations
posted by Anna .
I am not great at equations... I keep practicing and working these problems and questions out but I always seem to get different answers can someone please guide me on how or tell me the correct way to work these problems out>>
The linear equation
y=0.15x + 0.79
represents an estimate of the average cost of gas for year x starting in 1997. The year 1997 would be represented by x = 1, for example, as it is the first year in the study. Similarly, 2005 would be year 9, or x = 9.
a)What year would be represented by x = 4?
My answer is = year 2000
b)What xvalue represents the year 2018?
x= 22
c)What is the slope (or rate of change) of this equation?
How or where do I start on this one??
d)What is the yintercept?
e)What does the yintercept represent?
f)Assuming this growth trend continues, what will the price of gasoline be in the year 2018? How did you arrive at your answer

represents an estimate of the average cost of gas for year x starting in 1997. The year 1997 would be represented by x = 1, for example, as it is the first year in the study. Similarly, 2005 would be year 9, or x = 9.
a)What year would be represented by x = 4?
My answer is = year 2000
2000 is correct. You might make the next part easier by looking at how this was done, instead of just counting up 4.
1996 + 4 = 2000.
b)What xvalue represents the year 2018?
1996 + 18 = ??
x= 22
c)What is the slope (or rate of change) of this equation?
The equation for a straight line is
y = mx + b where m is the slope. The equation given is
y=0.15x + 0.79; therefore, 0.15 is the slope.
How or where do I start on this one??
d)What is the yintercept?
The y intercept is the 0.79 in the original equation. It is the point at which the line crosses the y axis (and x = 0 at that point).
e)What does the yintercept represent?
See answer above.
f)Assuming this growth trend continues, what will the price of gasoline be in the year 2018? How did you arrive at your answer
Use the equation, plug in x for the number of years (check me out but I think that will be 22) and solve for y. 
thank you dr. bob