Answer: 1/3 (x + 6)
Explanation: given f(x) = 3x - 6.
Let y = f(x) and so y = 3x - 6.
Trade places between x and y.
x = 3y - 6
Solve for y
x + 6 = 3y
y = x + 6/3
Now the new y is the inverse and so y = f-1(x)
f-1(x) = 1/3(x + 6)
Equation :
This parabola is facing downwards and highest point of the parabola is it's vertex.
Highest point is (-2,2)
so the vertex is (-2,2)
The graph is passing through (-1,0)
Equation in vertex form is


Substitute back in Equation

the graph has two x intercepts -1 and -3
that means (x+1) and (x+3) are the factors
multiply factors to get the equation in standard form

-2x^2-8x-6=0