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Find two positive numbers such that their product is 196, and the sum of the first plus four × the second is a miniμm.

A. 7, 28
B. 14, 14
C. 2, 98
D. 4, 49

User Doug Lee
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1 Answer

4 votes

Final answer:

To find the minimum sum of one number and four times another with a product of 196, we find that the pair (14, 14) results in the smallest sum, making Option B the correct answer.

Step-by-step explanation:

To find two positive numbers whose product is 196 and for which the sum of the first number plus four times the second is a minimum, let's designate the first number as x and the second as y. So, we have:

  • x × y = 196
  • x + 4y is to be minimized

Since the product of x and y is 196, the possible pairs of numbers (x, y) that multiply to 196 could be (1, 196), (2, 98), (4, 49), (7, 28), and (14, 14). For each pair, we can calculate x + 4y:

  • For (1, 196), we get 1 + 4(196) = 785
  • For (2, 98), we get 2 + 4(98) = 394
  • For (4, 49), we get 4 + 4(49) = 200
  • For (7, 28), we get 7 + 4(28) = 119
  • For (14, 14), we get 14 + 4(14) = 70

The pair (14, 14) provides the minimum sum of the first number and four times the second, which makes Option B the correct answer.

User Dronz
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