16Hit1600
AlgebraEasy–MediumEquation from slope and y-intercept

Algebra practice question

Which equation represents the line in the xy-plane with slope 4 and y-intercept −7?

  1. A. y = 4x − 7Correct
  2. B. y = −7x + 4
  3. C. y = 4x + 7
  4. D. y = −4x − 7

Answer: A. y = 4x − 7

In y = mx + b, m is the slope and b is the y-intercept. With m = 4 and b = −7: y = 4x − 7.

Why the other answers are wrong

B. y = −7x + 4
This swaps the slope and the y-intercept.
C. y = 4x + 7
The y-intercept is −7, so the constant is −7, not +7.
D. y = −4x − 7
The slope is 4, not −4.

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