Point-slope form is y - y₁ = m(x- x₁)
Where (x₁,y₁) is a point that passes through the line and m is the slope.
We are given the point (-4,6) and a slope of 3/4.
Now, in the equation you were given, the slope is -3/4. But it states that the slope is 3/4. You might want to check on that. I'll go with the slope as 3/4.
The point-slope form would be:
y - 6 = (3/4)(x - (-4)
y - 6 = (3/4)* (x + 4)
y- 6 = 0.75(x + 4)