That means you need a line with slope 6 and passes through (5, 3).
The slope formula states that if you have a line which has slope a and which passes through the point (b, c), the formula of the line will be (y - c) / (x - b) = a
Hence, we have:
(y - 3) / (x - 5) = 6
y - 3 = 6(x - 5)
y - 3 = 6x - 30
y = 6x - 30 + 3
y = 6x - 27, which is the equation we need.