
Carson M. answered 03/29/20
Dedicated and Experienced Academic Tutor -- Mathematics Specialty
The equation of the line with an x-intercept of 2 and a y-intercept of 4 can be written in the form y = mx + b
- At any x-intercept in the coordinate plane, the corresponding y-value is 0
- It can be said the line has an x-intercept at the point (2, 0)
- At any y-intercept in the coordinate plane, the corresponding x-value is 0
- It can be said the line has an y-intercept at the point (0, 4)
- Knowing two distinct points in a given line enables us to calculate the slope of the line
- Recall the Slope Formula — m = (y2 - y1) / (x2 - x1)
- m = (4 - 0) / (0 - 2)
- m = 4 / (-2)
- m = -2
- Substituting this into Slope-Intercept Form yields y = -2x + b
- By definition of "slope-intercept," the value of b is equal to the y-coordinate of the y-intercept, so it can be determined that the resulting linear equation is y = -2x + 4
- However if you don't know the y-intercept (unlike this particular case), the linear equation can be proven by substituting a coordinate pair along the line into the equation to solve for b as follows:
- y = -2x + b
- (4) = -2(0) + b
- b = 4
- or
- (0) = -2(2) + b
- b = 4
- Therefore, the equation of the line with an x-intercept of 2 and a y-intercept of 4 can be written in the form y = -2x + 4 or y = 4 - 2x where m = -2 and b = 4