AlgebraHardEquation of a line from a graph description
Algebra practice question
A line in the xy-plane has a y-intercept of −4 and passes through (2, 2). Which equation represents the line?
- A. y = 3x − 4Correct
- B. y = 3x + 2
- C. y = −4x + 2
- D. y = (1/3)x − 4
Answer: A. y = 3x − 4
Slope from (0, −4) to (2, 2): (2 − (−4))/2 = 3. Equation: y = 3x − 4.
Why the other answers are wrong
- B. y = 3x + 2
- 3x + 2 has y-intercept 2, not −4.
- C. y = −4x + 2
- −4x + 2 swaps the roles of the numbers.
- D. y = (1/3)x − 4
- 1/3 is the reciprocal slope.
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.