Hi!
I think Grace needs to wash at least 6 cars. Please tell me if I'm wrong.
Thank you
Answer:
20ft
Step-by-step explanation:
We have two unknowns, the length and the width of the floor. Let us represent this by l and w respectively.
Firstly, we are told that the length of the floor is twice its width. This mathematically means that l = 2w
The width of the rectangular carpet is 2ft less than the width of the floor but the floor length is equal. This means that the width of the floor is (w - 2)ft
Now we are told that the area of the rectangular carpet is 160 sq.ft
This means the length of the carpet multiplied by the width is 160
Mathematically:
l * (w-2) = 160
We know that l = 2w, if we substitute this:
2w(w - 2) = 160
w(w -2) = 80
w^2 -2w = 80
w^2 - 2w - 80 = 0
w^2 -10w + 8w -80 = 0
w(w -10) + 8(w - 10) = 0
(w + 8)(w -10) = 0
w = -8 or 10
Since distance cannot be negative, we ignore the -8 and use the 10 only
Hence the width is 10ft
The length is 2 times the width. The length is thus 2 * 10ft = 20ft
The lowest score you can earn on the next test and still achieve an average of at least an 88 is 107
<h3>Mean of data</h3>
Mean is the average of numbers.
Mean = sum of data/sample size
Let the lowest score be "x" such that;
Mean = 74+78+90+91+x/5
88 = 74+78+90+91+x/5
88(5) = 74+78+90+91+x
440 = 74+78+90+91+x
440 = 333 + x
x = 440 - 333
x = 107
Hence the lowest score you can earn on the next test and still achieve an average of at least an 88 is 107
Learn more on mean here: brainly.com/question/20118982
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N in 5n + 5 = 45 is 8 because you'd subtract 5 from 45 and get 40, then divide 40 by 5 and get 8.
