Answer:
I think that would be R
Step-by-step explanation:
A Variable is a symbol for a number we don't know yet. It is usually a letter like x or y. A number on its own is called a Constant.
Yes that is true, all opposite sides would be parallel, and all the corners are 90 degrees, then yes it is true
Do you by any chance have a photo of the problem?
21 chaperones are needed for 420 students.
Step-by-step explanation:
No. of juniors = 148
No. of seniors = 272
Total = 148+272 = 420 students
3 chaperones = 60 students
1 chaperone = 
Ratio of chaperon to students = 1:20
Let,
x be the number of chaperons for 420 students.
Ration of chaperones to students = x:420
Using proportion
Ratio of chaperones to students :: Ratio of chaperons to students

Product of mean = Product of extreme

Dividing both sides by 20

21 chaperones are needed for 420 students.
Keywords: ratio, proportion
Learn more about ratios at:
#LearnwithBrainly
Answer:
a=0
Step-by-step explanation:
x²-2x+y²-4y-4=0
(x²-2x+1)+(y²-4y+4)-9=0
(x-1)² + (y-2)² = 3²
Center: (1,2) radius: 3
(1,2) on line 2x-y+a=0
2*1 - 2 + a = 0
a = 0