Questions :
What is the equation of line through (0,4) with slope -1 ?
Options :
- y = -x + 4
- y = x – 4
- y = -x – 4
- y = x + 3
correct answer : a)
Explanation :
The equation of a straight line in slope-intercept form is y = mx + c, where m is the slope and c is the y-intercept. Here, the slope is -1 and the line passes through (0,4). Since the point has x = 0, the y-coordinate 4 becomes the y-intercept. Substituting the values gives y = -1x + 4, or y = -x + 4. Therefore, option (a) is correct. Option (b) has a positive slope of 1, which is incorrect. Option (c) has the correct slope but an incorrect y-intercept of -4. Option (d) also has a positive slope and an incorrect intercept.