Solve the following simultaneous equations for x and y. 2x+5y=9 and 4x-3y=7

Here the best method to use will be elimination since using a substitution for x or y may produce some nasty fractions. The first thing to look for is that the 2x and 4x are nice multiples of each other. As a result we should try to eliminate the x terms. So if we multiply equation 1 by 2 we reach 4x+10y=18. (Call this equation 3). Now we subtract equation 2 from equation 3. This gives 13y=11. So y=11/13. Now we substitute this y value into either equation, lets use 1. 2x+(511/13)=9 so 2x=62/13 and therefore x=31/13. We can test our solutions to be sure in equation 2 and see that (431/13)-(3*11/13)=7

Answered by Jamie G. Maths tutor

7469 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Differentiate the following: 2x^2 + 3x -2


The equation the line L1 is y=3x-2 and the equation of line L2 is 3y-9x+5=0. Show that these two lines are parallel.


If a train leaves for a 130 mile journey at 1.30pm, and travels at a constant speed of 50 miles per hour, at what time will it arrive?


Solve the quadratic equation: 5x2+8x+2


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