Solve the simultaneous equations: y+4x+1=0 and y^2+5x^2+2x=0
y= -4x-1y2 = (-4x-1)2 = 16x2 +8x +1y2 +5x2 +2x = 0lets substitute what we found y2 equal to earlier, which gives us(16x2 +8x +1) + 5x2 +2x = 021x2 + 10x +1 = 0after factorising this we get(7x+1)(3x+1)so x = -1/7 and -1/3 given the y=-4x-1our answers must bewhen x=-1/7, y=-3/7x=-1/3, y=1/3
