Answer:
Step-by-step explanation:
Integer factors of 117 include ...
... 117 = 1×117 = 3×39 ≈ 9×13
The last factor pair is two factors that differ by 4. We can take these to be the dimensions of the rectangle.
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If you want to write an equation for width (w), it might be ...
... w(w+4) = 117
... w² +4w -117 = 0
The factorization problem for this quadratic is the problem of finding two factors of 117 that differ by 4. That is what we have done, above.
If you want to solve this by completing the square, you can to this:
... w² +4w = 117
... w² +4w +4 = 121 . . . . . add 4 = (4/2)² to complete the square
... (w+2)² = 121
... w + 2 = ±√121 = ±11 . . . . take the square root
... w = -2 ± 11 . . . . . we're only interested in the positive solution
... w = 9, then w+4 = 13 and the dimensions are 9 cm by 13 cm.
Answer:
Look at the description:
Step-by-step explanation:
The mistake is that they did not need to divide the radius by two since the radius is already half of the diameter. The area of a circle is pi*r^2. The second mistake they made was that they assigned pi the value of 3 which is wrong. After calculating, the area of the circle is 53^2pi = 8824.73mm^2
the answer is 17.5 kilometers