Answer:
It is increasing.
Step-by-step explanation:
Given the graph of a straight line, there are several ways to find its equation.
Method 1: This method works only if the y intercept is visible.
Find any two points, (x1, y1) and (x2, y2), on the line and substitute their coordinates into the following formula to get m:
Get b from inspection of the y intercept of the graph.
Substitute the numbers that you have obtained for m and b into the equation y = m x + b.
Method 2: This method works even if the y intercept is not visible.
As in method 1, find any two points, (x1, y1) and (x2, y2), on the line and substitute their coordinates into the following formula to get m:
Substitute the number that you obtained for m into the equation y = m x + b. Also, take one of the points, say (x1, y1), and substitute its coordinates into the equation. This gives:
y1 = m x1 + b
It may not look like it, but this equation has only one variable, b, and you can easily solve for it.
Substitute the numbers that you have obtained for m and b into the equation y = m x + b.
Method 3: This method has the advantage that it uses only algebra, not geometry, and can be applied to any type of function, not just the straight line:
Find two points, (x1, y1) and (x2, y2), that are on the line. Take the first point, (x1, y1), and substitute it into the straight line equation, y = m x + b. This gives:
y1 = m x1 + b
Similarly, take the second point, (x2, y2), and substitute it into the straight line equation, y = m x + b. This gives:
y2 = m x2 + b
Together, these two equations constitute a system of two equations in the two unknowns, m and b. We can solve them for m and b using the elimination method. To be specific, if we subtract the first equation from the second, then b is eliminated and we get the equation:
y2 − y1 = m x2 − m x1,
which, when solved for m, gives the same equation as in the other two methods, namely:
Find b by back-substitution. To be specific, substitute the number that you obtained for m into one equation of the system of equations, say into y1 = m x1 + b. It may not look like it, but this equation has only one variable, b, and you can easily solve for it
. We have that C=18500$ and hence that 18500=x*1.562. Thus, solving for x we have that x=11841$.