Open Middle®
Directions: Using the digits 1 to 9, at most one time each, place a digit in each box so that 2 of the lines are parallel and the third line is a transversal.
Hint
What do we know about the slopes of parallel lines and transversals?
Answer
There are multiple answers but two of the lines must be parallel (have the same slope) and the third must have a different slope. One solution is 6x + 3y = 9, 4x + 2y = 8, x + 7y = 5
Source: Shelli Foust