Question 138619
The way I like to approach these problems is analyze the two sequences of numbers.

Sequence of x -2, -1, 0, 1, 2
In this sequence, each successive value of x, moving to the right, is 1 greater than the previous value.

Sequence of y -5, -2, 1, 4, 7
In the y sequence, each successive value of y, moving to the right, is 3 greater than the previous value.

From that information, we can see that an increase of x by 1 creates an increase in y by 3.

Let's guess y = 3x. Now, test your guess. If x = 0, then y would be 0. Wait, the sequences given as the problem state that when x is 0, then y is 1. 

Let's adjust our guess to be {{{y = 3x + 1}}}. Now test it again. We know it works for x = 0. Let's try x = 2. When x=2, then y = 3*2 + 1 = 7. Test some others as well.


So what does our equation tell us?
It tells us that the two sequences are related. They form a line. The line has a slope of 3 and crosses the y axis as the point (0,1)

{{{graph(600, 400, -10,10,-10,10, 3x+1) }}}