If x^2 + y^2 = 20 and y=10 - 2x, find x and y.

First work out y2 using the second equation, making sure to do this using the FOIL technique. Then substitute this into the first equation to get 5x2 - 40x - 80 = 0. All the terms in this can be divided by 5 to get x2 - 8x +16=0. Then factorise this to get (x-4)2=0. Therefore, x=4. Putting this value of x into the second equation gets the result of y=2

ST
Answered by Sara T. Maths tutor

8143 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

If f(x)=8x-3, what is the inverse function?


50 people ate a snack , some had apples some had biscuits the rest had banana. 21 people were male the rest female. 6 out of 8 people who had apples were female. 18 people had biscuits. 9 females had bananas. How many males had biscuits?


express the number 84 as a product of its prime factors


Write 2x^2 + 16x + 26 in the form a(x + d)^2 + e where a, d, and e are integers.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences