This is a ratio problem. First, we need to add the number of students polled.
7 + 4 + 3 + 6 = 20
Next, look at how many out of 20 students selected Science.
3 out of 20.
Say it this way:
3 is to 20 as ? is to 400.
Express it this way:
3/20 = x/400
Cross multiply to eliminate the denominators.
3 x 400 = 20 x Now solve for x.
1200 = 20 x
x = 60
Check it!
Does 60/400 reduce to 3/20? Yes!
60 students are predicted to select science out of 400
Answer
equation: 2(3x-9) + 2(2x+4)= 60
length: 36 meters
width: 24 meters
Step-by-step explanation:
2(3x-9) + 2(2x+4)= 60
6x-18 + 4x +8 =60
60+18-8= 10x
70=10x
x=7
length- 2(2(7)+4) = 36
width- 2(3(7)-9)= 24