Question

What is the equation of the graphed line?

y = -x - 3


y = x + 4


y = -x - 6


y = -x + 3

Answer 1

`y=-x-3`

Explanation:

From the graph, we observe that the y-intercept of the line is c=-3.

So, the equation of the line is, where m is the slope:

`y=mx+c= > y=mx-3---(1)`

Since the line contains the point (x,y)=(-3,0), substitute x=-3 and y=0 into (1):

`0=m(-3)-3\\0=-3m-3\\3m=-3\\m=-(3)/(3)= > m=-1---(2)`

Substitute (2) into (1), and we get:

`y=-x-3`