One line passes through the points (-2,3) and (0,-3) , it means the y intercept is b=-3
and slope m = 

So the equation of line will be 
And the inequality should be 
Or 
And the other line passes through (-2,3) and (0,2)
So the y intercept is b=2
and the slope is 
So the equation of line will be 
Or

So answer is 
Ok , with that information we can write the equations
x + y = 6
5x + 4y = 28
Where x = how many people ordered chicken
and y = how many people ordered egg salad
Through elimination , we can set one of the variables in both equations equal so we can eliminate it :
(4)x + (4)y = (4)6
5x + 4y = 28
4x + 4y = 24. equation 1
5x + 4y = 28. equation 2
Now we can subtract the second equation by the first equation and isolate one variable:
equation 2 - equation 1
5x - 4x + 4y - 4y = 28 - 24
x = 4
Now that we discovered our x value ( How many people ordered chicken salad ) , we can apply it to one of the equations and discover y ( how many people ordered egg salad)
x + y = 6
x= 4
4 + y = 6
We can shift 4 to the other side of the equation by subtracting 4 from both sides of the equation:
4 - 4 + y = 6 - 4
y = 2
x=4 and y=2
So the awnser is :
4 people ordered chicken salad and 2 people ordered egg salad!
I hope you understood my brief explanation!!
p.s if you want to know how to use another method to solve these problems ( Substition) , just let me know in a comentary down here
Let S(t) denote the amount of sugar in the tank at time t. Sugar flows in at a rate of
(0.04 kg/L) * (2 L/min) = 0.08 kg/min = 8/100 kg/min
and flows out at a rate of
(S(t)/1600 kg/L) * (2 L/min) = S(t)/800 kg/min
Then the net flow rate is governed by the differential equation

Solve for S(t):


The left side is the derivative of a product:
![\dfrac{\mathrm d}{\mathrm dt}\left[e^{t/800}S(t)\right]=\dfrac8{100}e^{t/800}](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dt%7D%5Cleft%5Be%5E%7Bt%2F800%7DS%28t%29%5Cright%5D%3D%5Cdfrac8%7B100%7De%5E%7Bt%2F800%7D)
Integrate both sides:



There's no sugar in the water at the start, so (a) S(0) = 0, which gives

and so (b) the amount of sugar in the tank at time t is

As
, the exponential term vanishes and (c) the tank will eventually contain 64 kg of sugar.
6.66, with a bar on top of the last two sixes