If x & y = the following table what is the function of x?

Question

x = 1,2,3,4

Y = 1,3,5,7

Answer 1

notice that for every increase of 1 in the x, the y increases by 2
so slope = 2
or, more formally, take the fist two points
(1,1) and (2,3)
slope = (3-1)/(2-1) = 2

so y = 2x + b
sub in the first point (1,1)
1 = 2(1) + b
b = -1

y = 2x - 1

check the remaining points to make they satisfy the equation.
Hint: they do.