Question

Suppose the following pairs of points are points on a linear graph. Find the slope and -intercept of

the equation that would model the linear relationship.
(−5,5) (5,2)

Answer 1

y = (-3/10) + 7/2

in decimal,

y = -0.3 + 3.5

Step-by-step explanation:

Equation of a line in slope-intercept form is

y = mx + b

m = slope = rise/run = (y2-y1)/(x2-x1) for any two points (x1, y1) and (x2, y2)

b is the y-value where the line intercepts the y-axis and is the value of y when x = 0

We have two points (−5,5) (5,2)

So m = (2 - 5)/( 5 - (-5) ) = -3/(5 + 5) = -3/10

So equation of line is

y = (-3/10)x + b

Plug in one of the points into this equation to find b

Take point( 5, 2)
We get

2 = (-3/10)(5) + b

2 = -15/10 + b

2 = - 3/2 + b

Add 3/2 to both sides

2 + 3/2 = b

or

b = 2 + 3/2 = 4/2 + 3/2 = (4+3)/2 = 7/2

So equation of line is
y = -3x/10 + 7/2

In decimal,

y = -0.3 + 3.5