Solve the simultaneous equations: (1) y – 2x – 4 = 0 , (2) 4x^2 + y^2 + 20x = 0

Rearrange (1): y=2x+4

Subsitute this into (2): 4x²+(2x+4)²+20x=0

Simplify and collect like terms: 8x²+36x+16=0

Factorise: (2x+1)(x+4)=0

Therefore: 2x+1=0 -> x=-0.5  and x+4=0 -> x=-4

Substitute this into (1) to get values for y: y=3 and y=-4