The larger number is 30.
Set up your equation.
x + y = 25
The question tells us one number is 5 less than the other.
The equation now becomes
x -5 = 25
Add 5 to each side to isolate x.
x=30
5.6 in a fraction is 5 and 6/10, or 5 3/5. To get the mixed fraction, multiply the whole number (to the left) by the denominator (bottom of fraction), and add to the numerator (top of fraction). So 5 × 5 = 25 + 3 = 28. So it'd be 28/5.
Answer: 5
hrs
<u>Explanation:</u>
Jasper: 
per hr
Yolanda: 
per hr
Together: 
per hr
Jasper + Yolanda = Together
+ =
+ 
= 
3x + 21 = 7x
21 = 4x
= x
Here is our profit as a function of # of posters
p(x) =-10x² + 200x - 250
Here is our price per poster, as a function of the # of posters:
pr(x) = 20 - x
Since we want to find the optimum price and # of posters, let's plug our price function into our profit function, to find the optimum x, and then use that to find the optimum price:
p(x) = -10 (20-x)² + 200 (20 - x) - 250
p(x) = -10 (400 -40x + x²) + 4000 - 200x - 250
Take a look at our profit function. It is a normal trinomial square, with a negative sign on the squared term. This means the curve is a downward facing parabola, so our profit maximum will be the top of the curve.
By taking the derivative, we can find where p'(x) = 0 (where the slope of p(x) equals 0), to see where the top of profit function is.
p(x) = -4000 +400x -10x² + 4000 -200x -250
p'(x) = 400 - 20x -200
0 = 200 - 20x
20x = 200
x = 10
p'(x) = 0 at x=10. This is the peak of our profit function. To find the price per poster, plug x=10 into our price function:
price = 20 - x
price = 10
Now plug x=10 into our original profit function in order to find our maximum profit:
<span>p(x)= -10x^2 +200x -250
p(x) = -10 (10)</span>² +200 (10) - 250
<span>p(x) = -1000 + 2000 - 250
p(x) = 750
Correct answer is C)</span>
