Under a counterclockwise rotation about the origin of 90°
a point (x , y ) → (- y, x ), hence
A(2, 1 ) → A'(- 1, 2 )
Answer/Step-by-step explanation:
5. 21x + 4 = 22x - 2 (corresponding angles)
Collect like terms
21x - 22x = -4 - 2
-x = -6
divide both sides by -1
x = 6
6. (x + 72) + (x + 132) = 180 (linear pair)
x + 72 + x + 132 = 180
Add like terms
2x + 204 = 180
2x = 180 - 204
2x = -24
x = -12
7. 90 = 22x + 2 (vertical angles)
90 - 2 = 22x
88 = 22x
Divide both sides by 22
4 = x
x = 4
8. 12x + 10 = 13x + 3 (vertical angles)
Collect like terms
12x - 13x = -10 + 3
-x = -7
Divide both sides by -1
x = 7
9. 17x = 16x + 5 (alternate exterior angles)
17x - 16x = 5
x = 5
✔️17x
Plug in the value of x
17(5) = 85°
10. 21x - 6 = 20x (corresponding angles)
Add like terms
21x - 20x = 6
x = 6
✔️20x
20(6) = 120°
Using the combination formula, it is found that she can select the shirts in 775,200 ways.
The order in which the shirt are chosen is not important, hence, the <em>combination formula</em> is used to solve this question.
Combination formula:
is the number of different combinations of x objects from a set of n elements, given by:
In this problem:
- 3 shirts from a set of 17.
- Then, 3 shirts from a set of 20.
- They are independent, hence, to find the total, we multiply both combinations.
She can select the shirts in 775,200 ways.
To learn more about the combination formula, you can check brainly.com/question/25821700
