Solve the simultaneous equations: x^2 + 8x + y^2; x - y = 10.

Label the two equations.

x2 + 8x + y2 = 84 (1)
x - y = 10 (2)

Rearrange (2) to get y = x - 10 and substitute for y in (1) to get x2 + 8x + (x - 10)2 = 84. Expanding and collecting like terms gives 2x2 -12x + 16 = 0 (3). Dividing (3) through by 2 gives x2 - 6x + 8 = 0 (4). Factorising (4) gives (x - 2)(x - 4) = 0 so either x = 2 and y = -8 or x = 4 and y = -6.

Answered by Lewis T. Maths tutor

4642 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

7^6 x 7^3


How do you find the distance a ball travels if fired at speed u and angle theta from the ground?


How does finding the gradient of a line and the area under a graph relate to real world problems?


Can you differentiate y = (x^4 + x)^10


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