Answer:
-16
Step-by-step explanation:
Given the sequence:
b(n)=b(n−1)−7, where b(1)=−2
b(2)=b(2−1)−7
=b(1)−7
=-2-7
b(2)=-9
Therefore, the 3rd term of the sequence
b(3)=b(3−1)−7
=b(2)-7 (Recall b(2)=-9 from above)
=-9-7
b(3)=-16
The 3rd term of the sequence is -16.
This is the answer the x=3 and the y=2
Answer:
59y+1
Step-by-step explanation:
25 + 8 (7y - 3) + 3y
Distribute
25+56y-24+3y
Combine like terms
59y+1
Answer:
x = y = 22
Step-by-step explanation:
It would help to know your math course. Do you know any calculus? I'll assume not.
Equations
x + y = 44
Max = xy
Solution
y = 44 - x
Max = x (44 - x) Remove the brackets
Max = 44x - x^2 Use the distributive property to take out - 1 on the right.
Max = - (x^2 - 44x ) Complete the square inside the brackets.
Max = - (x^2 - 44x + (44/2)^2 ) + (44 / 2)^2 . You have to understand this step. What you have done is taken 1/2 the x term and squared it. You are trying to complete the square. You must compensate by adding that amount on the end of the equation. You add because of that minus sign outside the brackets. The number inside will be minus when the brackets are removed.
Max = -(x - 22)^2 + 484
The maximum occurs when x = 22. That's because - (x - 22) becomes 0.
If it is not zero it will be minus and that will subtract from 484
x + y = 44
xy = 484
When you solve this, you find that x = y = 22 If you need more detail, let me know.
There are 10 letters in the set {a, b, c, d, e, f, g, h, i, j} which is the pool of letters to choose from when making these three letter codes.
We have 10 choices for slot 1
Then 9 choices for slot 2. This is because we can't reuse the choice for slot 1
Then 8 choices for slot 3
Overall, there are 10*9*8 = 90*8 = 720 different permutations
Answer: 720
Note: you can use the nPr permutation formula with n = 10 and r = 3 to get the same answer