Step-by-step explanation:
this one is a "thousand times" more complex than the inequality question to put there.
still easy, yes, for an experienced person, but here it is clear you need to understand lines, coordination grids, and overall deal with 2 variables (here : x and y) and therefore 2 dimensions.
the general line function is typically presented as
y = ax + b
a is the slope. that is the ratio of "y coordinate change / x coordinate change" when going from one point on the line to another.
and b is the y-intercept (the y value when x = 0), giving us the information about the point, where the line crosses the y-axis.
and so, look for yourself, which of the 4 equations has a b of +3 ?
y = 3x no, b = 0
y = x + 3 yes, b = 3, this is correct
y + 3 = x hmm. let's first bring it into the normed form
y = x - 3 aha ! no, b = -3
y = x - 3 no, the same thing as before. b = -3