Answer:
<em>n</em> - <em>k</em> + 1
Step-by-step explanation:
This is assuming (because you did not say) that <em>n</em> and <em>k</em> are integers and <em>n</em> is greater than <em>k</em>.
Example: from 2 to 5 {2, 3, 4, 5} includes 5 - 2 + 1 = 4 numbers.
Example: from -6 to 4 includes 4 - (-6) + 1 = 11 numbers, namely {-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4}
The future value of the investment in dollars s
V = p + prt
where
p = principal, dollars
r = annual interest rate (in decimal form)
t = time, years
To determine p, write the formula as follows:
Factorize p out on the right side.
V = p(1 + rt)
Divide each side b (1 + rt).

Answer:
*the figure is shown in the attachment
Answer/Step-by-step explanation:
Since <XYZ and <YZX are said to be congruent, therefore, the side opposite to each of the angle are also equal. Therefore, ∆XYZ is an isosceles ∆.
Find the value of n by creating an equation to solve for n:
XY = (9n + 12) ft
XZ = (15n - 6) ft
XY = XZ (2 equal lengths of isosceles ∆)
9n + 12 = 15n - 6 (substitution)
Combine like terms
9n - 15n = - 12 - 6
-6n = -18
Divide both sides by -6
-6n/-6 = -18/-6
n = 3
Find the length of leg XY by substituting n = 3 into XY = (9n + 12) ft.
XY = (9(3) + 12) ft
XY = (27 + 12) ft
XY = 39 ft
Find the length of leg XZ by substituting n = 3 into XZ = (15n - 6) ft.
XZ = (15(3) - 6) ft
XZ = (45 - 6) ft
XZ = 39 ft
B = F / (S-C)
B - breaking point in units
F - fixed costs, S - selling price, C - cost per racket.
S-C is the profit on a single unit
B = 740000 / (77.59 - 39.72) = 19540.53
The breaking point is approached after selling 19541 units.