AlgebraMediumReading a coordinate off the intersection of two standard-form lines
Algebra practice question
In the xy-plane, the lines 2x − 5y = 11 and 4x + 5y = 7 intersect at the point (p, q). What is the value of q?
Answer: -1
Add the equations: 6x = 18, so x = 3. Then 2(3) − 5y = 11 → −5y = 5 → y = −1. So q = −1.
Common wrong answers
- If you answered 1
- 1 has the wrong sign: −5y = 5 gives y = −1.
- If you answered 2
- 2 is p + q.
- If you answered 3
- 3 is p, the x-coordinate.
More Algebra questions
- Medium
A system: 2x + y = 11 and x − y = 1. What is the value of x + y? - Medium
Which of the following describes all solutions to 4x − 9 ≤ 2x + 5? - Medium
A phone's battery percentage is modeled by P = 100 − 8t, where t is the number of hours since it was unplugged… - Medium
If y = 2x − 1 and 3x + y = 14, what is the value of x? - Medium
If |2x − 3| = 7, what is the sum of all possible values of x? - Medium
Line k has equation y = (2/3)x + 1. Which equation represents a line perpendicular to line k?
Not affiliated with the College Board. SAT is a trademark of the College Board.