Answer:
d) 4 + 7 - 2
Step-by-step explanation:
7 + 2 - 4 = 5
2 + 7 - 4 = 5
7 - 4 + 2 = 5
4 + 7 - 2 = 9
Answer:
x=-1/2
Step-by-step explanation:
-3(x-4)= -9(x-1)
-3x+12= -9x+9
-3x+9x= 9-12
6x= -3
x=-3/6
x= -1/2
The answer to 20+50 is 72
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
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