Solve the simultaneous equations: 3x + 4y = 5 and 2x – 3y = 9

To solve a simultaneous equation we use a method known as elimination. We choose to 'eliminate' or remove the X or Y term. To 'eliminate' x we must firstly determine the lowest common multiple 3 and 2 (as these are the values in front of x in both equations). The lowest common multiple is 6. Therefore, we multiple the first equation by 2 and the second by 3. This gives: 6x + 8y = 10 and 6x - 9y = 27. To 'eliminate' x when can then subtract the second equation from the first. This give us: 17y=-17. Thus, y = -1. We can then substitute y = -1 into the first equation such that 3x+4=5. Rearranging this equation gives, 3x=9. Hence x=9/3=3. Therefore, x=3 and y=-1.

Answered by Prasanna G. Maths tutor

3926 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

A curve (a) has equation, y = x^2 + 3x + 1. A line (b) has equation, y = 2x + 3. Show that the line and the curve intersect at 2 distinct points and find the points of intersection. Do not use a graphical method.


A triangular prism has mass 900g, length 20cm and the triangle bases are equilateral and with side length 6cm. Find the density(g/cm^3) of the material the prism is made of.


Here are the first four terms of a quadratic sequence: 11 26 45 68. Work out an expression for the nth term.


How can I find the size of an angle in a right-angled triangle if I know the lengths of two of the sides?


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