Solve the simultaneous equations: y = 4x^2 - 9x - 1 and y = 5 - 4x

Subtract the second equation from the first, giving you: 4x^2 -5x -6

Factorise the quadratic: (4x + 3)(x - 2)

x = -0.75

x= 2

Now substitute these values into one of the equations (or both, just to double-check) and get your y value.

y = 5 - 4(-0.75)

y = 8

y = 5 - 4(2)

y = -3

Answer: 

x = 2     y = -3

x= -0.75     y= 8