So first. You need to convert to y = mx + b form, so to do that, subtract 5x from both sides, and you will have -6y = -5x + 9
Next, you need to divide by -6, and you get y = 5/6x + 1.5
Its good to note that for finding an equation that is perpendicular to that that equation, the slope is the opposite reciprocal. So, for the slope of your new line it is -6/5x.
So slope intercept form is y-y1 = m(x - x1) so to plug that in with the coordinates (-3, 5) you would have y - (-3) = -6/5(x - 5)
Then add the opposite and do the distributive property on the right side of the equation, so its y + 3 = -6/5x + 6
Then you would solve for y so subtract 3 and you end up with:
y = -6/5x + 3