16Hit1600
AlgebraVery hardProduct of the coordinates of an intersection

Algebra practice question

In the xy-plane, the lines 2x + y = 8 and x − 2y = −1 intersect at a single point. What is the product of the coordinates of that point?

Answer: 6

From the second equation x = 2y − 1; substituting, 4y − 2 + y = 8, so y = 2 and x = 3. The product is 6.

Common wrong answers

If you answered 1
1 is x − y.
If you answered 5
5 is the sum of the coordinates.
If you answered -6
−6 has the sign of y wrong.

More Algebra questions

Not affiliated with the College Board. SAT is a trademark of the College Board.