He would need to sell 28 because
12.50*28=350 and 350+50=400
Answer:

Step-by-step explanation:
So you have (16, 1)
When two linear functions are parallel, they have the same slope.
So function q also has a slope of 1/3x. You have a set of points so you can plug them in a slope intercept equation to find b.
y= mx+b
m= slope
y= y-intercept
1= 1/3(16) +b
1 - (16/3) = b
b= -13/3
so then, 
Drawing it out, as seen, using the Pythagorean theorem we get that w^2+l^2 (with w=width and l=length)=diagonal^2=24^2+l^2=40^2. Subtracting 24^2 from both sides, we get 40^2-24^2=l^2=1024. Square rooting both sides, we get l=32. Since the perimeter is 2w+2l, we get 32*2+24*2=64+48=112
Answer:
c = 2.25
Step-by-step explanation:
f(x) is a continuous and differentiable function on the interval, so the Mean Value Theorem guarantees a value for c exists.
The average slope is ...
m = (f(4) -f(1))/(4 -1) = (24 -12)/3 = 4
The point at which the derivative is 4 is ...
f'(c) = 6/√c = 4
√c = 6/4
c = 2.25