Solve the following simultaneous equations to obtain values for x and y: 2x + y = 7 & 3x - y = 8.

Label your equations 1 and 2 respectively. Make y the subject of equation 2 by taking away 3x from both sides and multiplying both sides by -1, to get y = 3x - 8. Now substitute this into equation 1 (i.e. replace the 'y' in equation 1 with '3x - 8'), giving 2x + (3x - 8) = 7. By grouping like terms together and adding 8 to both sides we get 5x = 15. Now to obtain our value of x simply divide both sides by 5, hence x = 3. Now use this value of x to find y. Substitute x = 3 into equation 2. So 3(3) - y = 8. This gives 9 - y = 8. By subtracting 9 from both sides and multiplying both sides by -1, we can get our value of y, giving y = 1. 

PM
Answered by Pratham M. Maths tutor

3264 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve y = x^2 + 3x + 2 = 0


How do I find the roots of a quadratic equation?


x^2 - y = 14, y - 2 = 6x, solve these equations simultaneously


Find the length of the hypotenuse if the right angled triangle's other two sides are of length 5cm and 12cm.


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