Question

Find the equation of the line shown

Answer 1

Explanation:

When we know both the x- and y-intercepts of a line, we can conveniently use the intercept form.

Let

A=x-intercept=9

B=y-intercept=9

the intercept form of the equation is therefore

x/A + y/B =1

substituting numerical values,

x/9 + y/9 =1 ..........................(1)

Factoring the identical denominators

(x+y)/9 = 1

Cross multiply

x+y = 9 ...............................(2)

Both (1) and (2) are valid forms of equation of the given line.

Answer 2

From the graph, the y-intercept is 9 and the slope is -1 so the equation is y = -x + 9. We know the slope is -1 because when x goes up by 1, y decreases by 1.