Your picture has several issues.
- x is not defined. It appears to be the number of apartments rented.
- R(x) is defined two different ways. The first way, it looks like it is the revenue from a single apartment. The second way, it looks like it is the revenue from the entire apartment complex.
- The derivative is in error. It should be -20x +2000. In any event, this is not the derivative you want. You're not trying to maximize revenue; you're trying to maximize profit.
- It might be useful to write an equation for profit: P(x) = R(x) -200x = -10x² +1800x. Then when you go to maximize it, your derivative will be P'(x) = 0 = -20x +1800 ⇒ x = 90.
Your answer is correct, but the path you followed to get there has a few potholes.
9514 1404 393
Answer:
Step-by-step explanation:
First of all, subtract 12 from both sides of the equation to put it into standard form:
3x² +8x -12 = 0
Then identify the a, b, c of this form:
ax² +bx +c = 0
You see that a=3, b=8, c=-12.
Now use those values in the quadratic formula for the solutions:
For this you need to know your angles in parallel lines.
3y will equal 87 as they are opposite angles and opposite angles are equal.
So y = 87/3
We can use the knowledge that angles in a straight line (in parallel line diagrams) will add up to 180. Therefore we do 180-87= 93. Now we know 3x=93 because just like the first example they are opposite angles. Now we know x=93/3.
(I didn’t have a calculator on me so you’ll have to work out the final result. Also I recommend looking into angles in parallel lines. I tried my best to explain so I hope you understand the jist of what I was trying to say.)
Use the foil method to multiply out the expressions. Then solve for x by first combining like terms and then using inverse properties
Alright so I'm coming up with this on the fly; you have the first six letters (a,b,c,d,e,f) and 0-9 and your ten numbers. calculate the amount of possible combinations for the letters by simply writing them down.
ab, ac, ad, ae, a f- five
bc, bd , be, bf- four
cd, ce, cf- three
de, df- two
ef,- one.
adding these all together gets a total of 15 for the letters. now the numbers
01, 02, 03, 04, 05, 06, 07, 08, 09- nine
12, 13, 14, 15, 16, 17, 18, 19- eight
23, 24, 25, 26, 27, 28, 29- seven
34, 35, 36, 37, 38, 39- six
45, 46, 47, 48, 49- five
56, 57, 58, 59- four
67, 68, 69- three
78, 79- two
89- one
added together with a total of 45 combinations.
alright so, 45 different number combinations and 15 letter combinations. multiplying 15 by 45 should tell you the total possible combinations for a two letter and two number serial-number
