Question

Y

10-
9
8
7
6
5
4
3
2
1
1 2 3 4 5 6 7 8 9 10
What is the equation of the blue line?
X
please help

Answer 1

y = 3x + 1

the equation is in gradient- intercept form as this is linear (y = mx + c).

c is the y intercept, which is where the line crosses the y-axis and x = 0 (vertical line). in this, it passes through at the point (0, 1). so c (y-intercept) = 1.

m is the gradient of the line. it is calculated by rise/run (y2 -y1/x2-x1). so pick two points. here, we'll pick (4,1), and (0,1).

so:

(4-1)/(1-0) = 3/1

which is simply 3.

so, m =3

we put these numbers into y = mx + c and you get:

y = 3x + 1