AlgebraHardPoint on a line whose x-coordinate is twice its y-coordinate
Algebra practice question
In the xy-plane, a point on the line y = 3x − 7 has an x-coordinate that is twice its y-coordinate. What is the y-coordinate of that point?
Answer: 7/5 or 1.4
Set x = 2y: y = 3(2y) − 7 = 6y − 7 → 5y = 7 → y = 7/5.
Common wrong answers
- If you answered 7
- 7 comes from y = 6y − 7 solved as y = 7.
- If you answered 14/5
- 14/5 is the x-coordinate, not y.
- If you answered -7/5
- −7/5 has the wrong sign: 5y = 7.
More Algebra questions
- Hard
For how many integer values of x is −2 < (x − 5)/3 ≤ 1 true? - Hard
The system 2x + 3y = 6 and 4x + 6y = k has infinitely many solutions. What is the value of k? - Hard
Which of the following is the complete solution set to |x − 4| < 6? - Hard
A student has $40 to spend on notebooks costing $4 each and pens costing $2 each, and wants at least 12 items … - Hard
What is the least whole number of minutes of international calling in a month for which the total monthly cost… - Hard
How many liters of the 30% acid solution did the technician use?
Not affiliated with the College Board. SAT is a trademark of the College Board.