Which line has a slope of 1/3and goes through (3, - 1) ?

Let's look at it like this: Do you the formula for any line (You might have heard it as slope-intercept form) ?

Y = mx + c.

Where m is slope, and c is the vertical intercept.

y = (1/3) x + c. Since it passes through (3, - 1) it will satisfy the equation

x = 3, y = - 1

-1 = (1/3) * 3 + c.

-1 = 1 + c

-1 - 1 = c

-2 = c

c = - 2

y = (1/3) x - 2. Multiply through by 3

3*y = 3 * (1/3) * x - 2*3

3y = 1x - 6

3y = x - 6