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

AT

Related Maths A Level answers

All answers ▸

Find the minimum value of the function, f(x) = x*exp(x)


y =(4x)/(x^2+5) (a) Find dy/dx, writing your answer as a single fraction in its simplest form. (b) Hence find the set of values of x for which dy/dx<0


Find an equation of the circle with centre C(5, -3) that passes through the point A(-2, 1) in the form (x-a)^2 + (y-b)^2 = k


When given an equation in parametric form, how can you figure out dy/dx?