Answer:
3/2 =x
Step-by-step explanation:
These two angles are interior angles. They add up to 180 degrees
20x+5 = 24x-1
Subtract 20x from each side
20x-20x+5 = 24x-20x-1
5 = 4x-1
Add 1 to each side
5+1 =4x-1+1
6 =4x
Divide by 4
6/4 = 4x/4
3/2 =x
Answer:
144
Step-by-step explanation:
just did it
Answer:
66
Step-by-step explanation:
If there are <em>n</em> students, then the number of pairs is
.
With 12 students,
pairs can be formed.
The reason the formula works is this: Each of the 12 students can be paired with 11 other students (no student is paired with him/her self). But counting 12 x 11 = 132 counts each pair <u>twice</u>. Example: student A can be paired with student B,..., student B can be paired with student A. The pair was counted two times.
See the attached image that shows pairings of 5 students. There are
5(5 - 1)/2 = 5(4)/2 = 10 pairs.