Question

need linear equation for
x y
1 20
2 17
3 14
4 11

Answer 1

for every increase of 1 in x, y decreeases by 3

this gives us 3x

y=0=23

so, y=23-3x

Answer 2

y = 20, 17, 14, 11
x = 1, 2, 3, 4

change in y--
17 - 20 = -3
14 - 17 = -3
11 - 14 = -3

change in x--
2 - 1 = 1
3 - 2 = 1
4 - 3 = 1

Slope m = y difference/x difference
m = -3/1 = -3

y = mx + b
To find b using point (1,20)
m = -3

20 = -3(1) + b
20 = -3 + b
b = 23

Therefore, the equation is.
y = -3x + 23