Answer:
y = 3x - 5
Explanation:
You use the equation y = mx + b, and you plug in what you know. The slope is already 3 so you do y = 3x + b
after that, you plug in y and x, because (2,1) are the values of x and y.
1 = 3(2) + b
1 = 6 + b
subtract 6 from both sides to isolate the b
-5 = b