We are going to use the equation of a line y = mx + b. In this equation, m is the slope and b is the y-intercept.
We know from the question that the slope is 1. Therefore, m = 1. So now, our line is y = 1x + b
Then, we can use a known point on the line to find b. We know that our line passes through the origin so point (0,0) is on the line.
0 = 1(0) + b
0 = 0 + b
b = 0
Therefore, the equation of the line is:
y = 1x + 0
or just y = x