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A first number plus twice a second number is 9 . Twice the first number plus the second totals 15 . Find the numbers.

User Na Pro
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1 Answer

3 votes

Answer:

  • 7 and 1

Explanation:

Let first number be x

Second number be y

According to the question, A first number plus twice a second number is 9 .

x + 2y = 9

x = 9 - 2y - - - - - (1).

Also Twice the first number plus the second totals 15

2x + y = 15 - - - - - (2).

Substitute equation (1) in equation (2),

→ 2x + y = 15

→ 2(9 - 2y) + y = 15

→ 18 - 4y + y = 15

→ 18 - 3y = 15

→ -3y = 15 - 18

→ -3y = -3

→ y = 1

Substitute the value of y in equation (1)

→ x = 9 - 2y

→ x = 9 - 2(1)

→ x = 9 - 2

→ x = 7

Hence, x = 7 and y = 1

Therefore, The required numbers are 7 and 1.

User Balogun
by
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