AlgebraMediumx-intercept after finding the constant
Algebra practice question
In the xy-plane, the line 5x − 2y = c passes through the point (2, −3), where c is a constant. What is the x-intercept of the line?
Answer: 16/5 or 3.2
c = 5(2) − 2(−3) = 16. The x-intercept is where y = 0: 5x = 16, x = 16/5.
Common wrong answers
- If you answered 16
- 16 is c, not the intercept.
- If you answered 4/5
- 4/5 comes from c = 4, computing 10 − 6 instead of 10 + 6.
- If you answered -8
- −8 is the y-intercept (16 ÷ (−2)).
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.