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3 years ago

7x + 2y = 17 (3x +2y = 3)

Mathematics

1 answer:

Gnoma [55]3 years ago

8 0

Step-by-step explanation:

Multiply second equation by -1

-1 × (3x + 2y) = 3

-3x -3y = -3 now add this to the first equation

7x +2y = 17

(-3x-2y)= -3

7x +2y -3x -2y = 17 -3 (2y will eliminate -2y)

4x = 14

x = 7/2 now by using this information we found we can calculate the value for y

if 3x + 2y = 3 (replace x by 7/2)

3 ×(7/2)+2y = 3 ➡ 21/3 + 2y = 3 ➡ 2y = 3 - 21/3 ➡ 2ty = 15/2 ➡ y = 15/4

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Answer:

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Step-by-step explanation:

Option 1:

It is necessary to accomplish one of the next conditions:

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Then, for the first condition:

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for the second condition:

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where 3C1 is a combination. The 3C1 determines which of the three digits is even, and it is necessary to subtract the numbers under 100 with the other 2 digits odd.

So, there are 450 numbers of three digits whose the sum of the digits is even.

Option 2:

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Answer:

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Step-by-step explanation:

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