Question

{(a, b), (a + 2, b - 4) }

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What is the equation for the line of best fit for this set of data?
y = - 2x
y = -2x + 2
y = -2x + 2a + b
y = -2x + 2a - b

Answer 1

`y=-2x+2a+b`

Explanation:

step 1

Find the slope

The formula to calculate the slope between two points is equal to

`m=(y2-y1)/(x2-x1)`

we have the ordered pairs

(a, b), (a + 2, b - 4)

substitute the values in the formula

`m=(b-4-b)/(a+2-a)`

`m=(-4)/(2)`

`m=-2`

step 2

Find the equation of the line in point slope form

`y-y1=m(x-x1)`

we have

`m=-2`

`point\ (a,b)`

substitute

`y-b=-2(x-a)`

step 3

Convert to slope-intercept form

`y=mx+b`

isolate the variable y

`y-b=-2x+2a`

`y=-2x+2a+b`