Solve the two simulatneous equations x^2+y^2=18 and x-y=3
1) X2 +2Y2= 18 2) X - Y = 3 Rearrange 2) in the form X=3-Y then substitute in to 1); (3-y)2 +2Y2=18, this is your new equation 3 9+3Y+3Y+Y2+2Y2=18 3) 9+6y+3Y2= 18 Divide equation 3) by 3 3 +2Y+Y2=6 Solve for Y by equating to zero then factorising in to double brackets; Y2+2Y -3 = 0 (Y+3)(Y-1)=0 when (Y-1)=0, Y =1 and when (Y+3)=0, Y=-3 solve x by substituting your found Y values in to equation 2 when Y=1; X-1 = 3 so X=4 When Y=-3; X--3=3, so X=0
RC
Related Maths GCSE answers
All answers ▸Use the quadratic formula to find the solutions to x^2+2x-35=0
For what values of k does the line y=kx-1 have two distinct points of intersection with the circle (x-2)^2+(y-3)^2=2?
i) Factorise x^2 – 7x + 12 ii) Solve x^2 – 7x + 12
The distance from the Earth to the Sun is 93 million miles. Assume: it takes 365 days for the Earth to travel once around the Sun and the Earth travels in a circle with the Sun at the centre. Work out the average speed of the Earth in miles per hour.