Find the exact value of c

Equation:  2*x + 3*y = 1470

1. Slope-intercept form: y = a*x + b,  where a is the slope and b is the y-intercept. Isolating y form the equation:

2*x + 3*y = 1470

3*y = 1470 - 2*x

y = (-2/3)*x + 1470/3

y = (-2/3)*x + 490

slope: (-2/3)

y-intercept: 490

2. First locate the y-intercept at (0, 490), then starting from this point, move 3 units to the right and then 2 units down, and draw this point, which is (3, 488). Finally, draw a line that pass through these 2 points

3. Function notation is the same as Slope-intercept form with y-variable replaced by f(x). For this case: f(x) = (-2/3)*x + 490. The graph of this function represent how many wrap lunch specials has to been sold to earn $1,470 in a month as a function of the number of sandwich lunch specials sold.

4. See figure attached.

5. The new equation is:  2*x + 3*y = 1593

In Slope-intercept form:

2*x + 3*y = 1593

3*y = 1593 - 2*x

y = (-2/3)*x + 1593/3

y = (-2/3)*x + 531

In comparison to the first case: