How do you write an equation of a line passing through (2,3) with x-intercept 4?

1 Answer
Jan 30, 2016

The x intercept is (4, 0), which is just another point on the line.

Explanation:

We can find the point slope form of the line but first we must find the slope of the line.

The formula for slope is m = #(y_2 - y_1)/(x_2 - x_1)#, where m represents slope, (#x_2, y_2#) and (#x_1, y_1#) represent separate points.

m = #(y_2 - y_1) / (x_2 - x_1)#

Let point 1 be (2, 3) and point 2 (4,0).

m = #(0 - 3)/(4 - 2)#

m = #-3/2#

Now that we know the slope we can use point slope form to find the equation of our line.

#y - y_1# = #m(x - x_1)#

We'll use the point (4, 0) for (#x_1, y_1#) but both points would give us the same end result.

y - 0 = #-3/2#(x - 4)

y = #-3/2x + 6#

Your equation is y = #-3/2x# + 6 with the slope being #-3/2# and the y intercept 6.

Practice Exercises:

  1. Find the equations of the following lines:

a). Has a y intercept of -3 and a slope of #2/5#

b). Passes through (-3,6) and (-1,7)

c) Has an x intercept of 2 and a y intercept of -9.

Good luck!