y = mx + b is the form used when you know the slope (m) and the y-intercept (b).

The x intercept occurs when y = 0. Therefore, the line passes through (-3,0).

So, now we know three values for the equation (m=3/4, x= -3, and y = 0), so we can solve for the y-intercept (b):

0 = (3/4 * -3) + b

0 = -9/4 + b

9/4 = b

Now that you know the slope and the y-intercept, you can write the equation:

y = (3/4)x + 9/4

The x intercept, as a point, is (-3, 0)

so plug those in for (x,y) to get b (you know m = 3/4):

y = 3/4 x + b

0 = 3/4 (-3) + b

0 = -9/4 + b

9/4 = b

so y = 3/4 x + 9/4