Jaeburd, this is the solution:
Part a: x-intercept
Let's substitute in 0 for y, as follows:
3x - 6 * 0 = 9
3x - 0 = 9
3x = 9
Dviding by 3 at both sides:
3x/3 = 9/3
x = 3
In consequence, x-intercept is (3, 0)
Part b: y-intercept
Let's substitute in 0 for x, as follows:
3 * 0 - 6y = 9
0 - 6y = 9
-6y = 9
Dividing by -6 at both sides:
-6y/-6 = 9/-6
y = -9/6
Simplifying at the right side:
y = -3/2
In consequence, y-intercept is (0, -3/2)