Question

Question #672cd

Answer 1

`y = -x+4 and y = 1/4x+14`

Explanation:

Slope-intercept form of the equation of a straight line is `y = mx+c`

`-1.1x-5.5y = -4.4" "larr` re-arrange the equation

`color(white)(........) -5.5y = 1.1x -4.4" "larr` divide by `-1.1`

`color(white)(..................)y = -x+4`

Do the same for the other equation:

`0.8x-3.2y = -11.2" "larr` re-arrange the equation

`color(white)(.....)-3.2y = -0.8x-11.2" "larr` divide by `-3.2`

`color(white)(................)y = 0.25x+14`

`color(white)(................)y = 1/4x+14`

Now plot the graphs.

The break-even point can be found from the point of intersection of the the two lines.
graph{(-x-y+4)(x/4-y+14)=0 [-21.75, 18.25, -2.72, 17.28]}