Solve the simultaneous equations 2x + 7y = 15 and 3x + 6y = 21

Find the lowest common multiple of 2 and 3, which is 6. Multiply each term in the first equation by 3, and each term in the second equation by 2 to produce two equations with the same coefficient of x (which is 6). The two resulting equations are 6x + 21y = 45 and 6x + 12y = 42. Now you need to cancel the x term by subtracting the second equation from the first which leaves you with 9y = 3, y =1/3. Now sub y=1/3 into any of the four equations to find an x value of 19/3.
Copy of method worked through ready to show in session

IR
Answered by Isobel R. Maths tutor

2947 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

s^2 - 2s - 24 = 0


Solve 5x – 2 > 3x + 11


How do I expand the following equation (x+4)(x+2)


Solve 3x + 6 > 3 - 2x.


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