Solve the equations x^2+y^2=13 and x-2y=1 simultaneously.

Rearranging the second equation gives x=2y+1. Substituting this into equation 1 gives (2y+1)2+y2=13.Rearrangingthis and factorising the quadratic equation gives (5y-6)(y+2)=0, givingsolutions of y=6/5 and y=-2.Thecorresponding x values are found by substituting these values into equation 2giving: x=17/5 and x=-3 respectively.

PS

Related Maths GCSE answers

All answers ▸

Algebraic fractions


Expand the brackets? (x+4)(2x-3)


Simplify the following: 2(3-2x) - 3(x+1)


Complete the square and find the roots (where y=0) of: "x^2+4x-5"