f4 maths5

1.Let f(x)=x^2-4x-5 and g(x)=f(x-2),find the x-intercepts of the graph of y=g(x)
2.P(2,8) lies on the graph of y=2x+b,If f(x)=(2x+b^2),slove f(x)=12(Leave the ans in surd form.)
3a.Slove the following simultaneous equations: x-4y=-3 & x^2-2xy=5
3b.Let m and n be positive integers.slove the following simultaneous equations: logm/n^4=-3 & (log m)^2-2 log m log n=5(leave the ans in index form)
4.Let f(x)=2x^3-x^2-5x-2 and g(x)=x^3-4x+x+6.x+1 is a common factor of f(x) and g(x).It is given that h(x)=3x^3-5x^2-4x+4=f(x)+g(x).Please slove the equation 3x^3-5x^2-4x+4=0.