Which ratios form a proportion? A. 9/45,8/40 B. 9/22,14/28 C. 8/12,12!15 D.8/12,12/21

Mathematics

1 answer:

saul85 [17]3 years ago

5 0

Answer: Choice A) 9/45 and 8/40

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If you divide both top and bottom of 9/45 by the GCF 9, you get 1/5

If you divide top and bottom of 8/40 by the GCF 8, you also get 1/5

So the original fractions must be the same

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Another way to check is to use a calculator and see that 9/45 = 0.2 and 8/40 = 0.2, so 9/45 = 8/40

Or you can subtract the fractions and you should end up with 0, so, 9/45 - 8/40 = 0

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You can also set up a proportion and cross multiply

9/45 = 8/40

9*40 = 45*8

360 = 360

The last equation is true, so the first equation must be true

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A college parking lot is 140 ft long and 90 ft wide. The college wants to increase the area of the lot by 29% by adding strips o

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The initial dimenssions of the park lot are:

length: 140 ft
width: 90 ft

initial area: 140 * 90 = 12,600 ft^2

Area increased 29% = 12,600 * 1.29 = 16,254 ft^2

width of the strips: x

New length: 140 + x

New width: 90 + x

New area: (140+x)(90+x) = 16,254

Solution of the equation:

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4 years ago

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Answer:

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Step-by-step explanation:

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