Question

Here are clues for a puzzle involving two numbers.

Seven times the first number plus six times the second number equals 31.
Three times the first number minus ten times the second number is 29.
PART A
What are the two numbers?

Answer 1

• the first number is 5 1/2
• the second number is -1 1/8

Explanation:

The relations describing the two numbers can be written as equations. First, we need to assign variables: let x and y represent the first and second numbers, respectively.

The given relations are then ...

7x +6y = 31

3x -10y = 29

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Such a system of equations can be solved many ways. One that is usually convenient is to use a graphing calculator. It tells us ...

• the first number is 5 1/2
• the second number is -1 1/8