Permutations
slot method
8 slots
1st slot has 8 choices
2nd has 7 because 1 went to first slot
3rd has 6
4th has 5
5th has 4
6th has 3
7th has 2
8th has 1
8*7*6*5*4*3*2*1=40320 ways
Let x be the expensive scarf. The other scarf costs x-3.
x + (x-3) = 25
2x = 28
x = 14
Answer: 14
Start with 7-4=3
Then 3x3=9
Then 18+9=27
Answer 27
(9x - 1)² = <em>81x² - 18x + 1</em>
Answer:
23. 16x² + 4x + 0.25
24. 16x² - 4x + 0.25
Step-by-step explanation:
Given the functions f(x) = 4x + 0.5 and g(x) = 4x - 0.5, questions 23 and 24 are asking you to square the entire function. So, you will take the expression given in each function and square it:
(f(x))² = (4x + 0.5)(4x + 0.5) Using FOIL:
(4x*4x) + (4x*0.5) + (4x*0.5) + (0.5*0.5)
16x² + 2x + 2x + 0.25 = 16x² + 4x + 0.25
(g(x))² = (4x - 0.5)(4x - 0.5) Using FOIL:
(4x*4x) - (4x*0.5) - (4x*0.5) + (0.5*0.5)
16x² - 2x - 2x + 0.25 = 16x² - 4x + 0.25
