X - number of customers

There can't be a fraction of the number of people, so there must be some mistake in the question.
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2x + 3y = 1,470
To solve using the slope intercept method, we need to solve for y.
First, subtract 2x from each side.
3y = -2x +1470
The, we need to divide both sides of the equation by by 3 to solve for y
y = -2/3 x + 490.
We know the y intercept is 470, which means on the y axis we place at point at positive 490. The slope is -2/3. We go down 2 units and over to the right 3 units and place a point. We draw a line connecting these two points extending only to the right until it reaches the x axis. We cannot have negative x because we cannot sell negative lunch specials. We cannot have negative y, because y is the number of specials sold.
Working together three workers would take 1 hour 36 minutes to finish the job
<em><u>Solution:</u></em>
Given that first worker can finish the job in 8 hours
So in one hour, first worker can do
th of the work
The second worker can finish the job in 4 hours
So in one hour, second worker can do
th of the work
The third worker can also finish the job in 4 hours
So in one hour, third worker can do
th of the work
<em><u>The three workers working together in 1 hour can do:</u></em>

The three worker can thus do
th of the work in one hour
Hence the three of them together can finish the work in
hours
hours
Thus working together three workers would take 1 hour 36 minutes to finish the job