Respuesta :
The equation of any straight line, called a linear equation, can be written as: y = mx + b, where m is the slope of the line and b is the y-intercept.
The slope m of this line can be calculated like this:
m = change in y-value / change in x-value
we are given (x₁,y₁) as (-3,-4) and (x₂,y₂) as (0,-1)
so slope m is:
m = (y₂ - y₁) / (x₂ -x₁)
= -1 - (-4) / 0 -(-3)
= 3 / 3
= 1
You can find the y-intercept by looking at the graph and seeing which point crosses the y axis. This point will always have an x coordinate of zero.
Now,
y = x + b (since the value of m has been calculated as 1 as shown above)
⇒ b = y - x
⇒b = -4 - (-3) [if we put in the values from our first point (-3, -4)]
⇒b = -1 is the y intercept
Note:
if we put in the values from our second point (0, -1) in b = y - x, then also we get b = -1 as the y intercept
