Solving simultaneous questions, e.g. 3x + y = 11 and 2x + y = 8

The unknowns in a simultaneous equation need to be solved, which in this case are x and y.The method I will be using is by elimination:First, find which unknown has the same coefficient. In this example this is the letter y that has a coefficient of 1 in both equations.Then, subtract the two equations from each other to eliminate y so you get:3x + y = 11-2x + y = 8-------------x = 3Now, you know what x is so you can substitute x back into any of the equations to rearrange and find yIn this case subbing into 3x + y = 113x + y = 113(3) + y = 119 + y = 11y = 2We have now found x = 3 and y = 2To check the answers are right, substitute this back into the second equation just for confirmation and this should work!

Answered by Simran S. Maths tutor

2224 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

ABC is an acute-angled triangle. BA=7cm and BC=8cm. The area of triangle ABC is 18 cm^2 . Work out the size of angle BAC. Give your answer correct to 3 significant figures. You must show all your working.


Work out an estimate for the value of (8.1 x 198)/0.0491


There are 30 balls in the bag, 10 of which are blue. Adam takes 2 balls out of the bag without a replacement and calculated that there is a probability of 0.2 of both balls being blue. What percentage error did he make compared to the true probability?


A)Write x^2 – 8x + 25 in the form (x – a)^ 2 + b. (B) Write down the coordinates of the turning point of the graph of y = x2 – 8x + 25. (C)Hence describe the single transformation which maps the graph of y = x2 onto the graph of y = x2 – 8x + 25.


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 2013–2024

Terms & Conditions|Privacy Policy
Cookie Preferences