Given f(x)=x+3 what is the range, when the domain is {-1,3,5,7}?

 Slope = -1

 x-intercept = 3/-1 = -3.00000

 f-intercept = 3/-1 = -3.00000

Slope = 0.667/2.000 = 0.333

 x-intercept = 3/-1 = -3.00000

 f-intercept = 3/3 = 1

Slope = 0.400/2.000 = 0.200

 x-intercept = 3/-1 = -3.00000

f-intercept = 3/5 = 0.60000

Slope = 0.286/2.000 = 0.143

 x-intercept = 3/-1 = -3.00000

 f-intercept = 3/7 = 0.42857

the answer is y < -3 or   y > 3

-3y > 7 + 2

-3 y > 9

y < -3