How do I solve this pair of simultaneous equations: 3x+y=7 and 3x-y=5?

Step 1: Eliminate the ‘y’ component from the equations by adding the equations together. This gives the new equation ‘6x=12’

Step 2: Find the value of x by dividing both sides of the equation by 6. This gives us the value of x=2.

Step 3: Use this value of x to find the value of y, by substituting x=2 into one of the two original equations. For example, using the first equation: 6+y=7. By subtracting 6 from both sides of the equation, we find that y=1.

Step 4 (optional but recommended): To check that these values of x and y are correct, substitute both these found values into the original equation that you haven’t already used. Using the second equation, we can verify that 3x-y=5 is correct when x=2 and y=1. We can therefore have full confidence that we have the correct answer!

Answered by Alisha M. Maths tutor

3853 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the inequality x^2 + 4x ≥ 77


[equ1] 3y − 6x = 3 [equ2] y y x 2 − x + 2 2 = 2


Simplify (2^2)^3


White paint costs £2.80 per litre and blue paint costs £3.50 per litre. White and blue paint are mixed in the ratio 3 : 2. How much does it cost to make 18 litres of this mixture?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences