Solve simultaneously: x^2+y^2=25 and y-3x=13

The substitution method means we have to rearrange the linear equation to find a variable, either x or y, then substitute it into the quadratic (and more difficult to solve) equation, as follows...x2+y2=25 y=3x+13x2+(3x+13)2=25x2+9x2+78x+169=2510x2+78x+144=05x2+39x+72Factorise...(5x+24)(x+3)=0x=-24/5, x=-3Sub in linear equation for y...when x=-24/5, y=-7/5when x=-3, y=4

Answered by Saffron C. Maths tutor

2583 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Simplify the following: 5(x+2) - 3(6-x)


Solve the simultaneous equations: 2x + y = 18, x - y = 6


Solve these simultaneous equations (1) 12x + 3.5y = 32 (2) 8x + 3y = 24


Fully simplify (8a^2b * ab^4)/(2a^3b^2)


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences