Solve the simultaneous equations: x^2+y^2=36 ; x=2y+6

Substitute x in terms of y into the first equation:

(2y+6)2+y2=36

Use FOIL to expand the brackets

4y2+24y+36+y2=36  =>   5y2+24y=0

y(5y+24)=0  =>  y=0   or    y=(-24)/5

Substitute these values of y into the second equation to find x

when y=0, x=2*0+6  =>  x=6

when y=(-24)/5,  x=2*(-24)/5+6  =>  x=-3.6

Answered by Daniel B. Maths tutor

30100 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Q = P / (R (4-t)), P=36, R= 3, t=-2


Solve: 3x + 4 = x + 12


Billy wants to buy 10kg of the same oranges. Type A comes in bags of 1.25 kg and costs £1.50. Type B comes in bags of 5kg and used to cost £6.60 but are now 15% off. Which type is more worth it for Billy and how much does it cost?


A flight travels at 750kmph for 7 hours and 18 minutes, work out the distance travelled? Then convert 750 km/h into metres per second.


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences