Direction: Consider the following for the items that follow:

Let L : x + y + z + 4 = 0 = 2x - y - z + 8 be a line and P : x + 2y + 3z + 1 = 0 be a plane. 

What is the point of intersection of L and P? 

Let z = [y] and y = [x] - x, where [.] is the greatest integer function. If x is not an integer but positive, then what is the value of z? 

If f(x) = 4x + 1 and g(x) = kx + 2 such that f o g(x) = g o f(x), then what is the value of k?  

What is the minimum value of the function f(x) = log₁₀(x² + 2x + 11)?