If 2x + y = 13 and 3x - y = 12, what are the values for x and y?

To solve these simulataneous equations we need to use substitution:If 2x + y = 13 then y = 13 - 2xTherefore 3x - y = 12 can be rewritten as 3x - (13 - 2x) = 12We can expand these brackets and solve for x:3x - 13 + 2x = 12-> 5x = 25--> x = 5Now we have the value of x, we can subsitute this into either of the initial equations to find the value of y:2(5) + y = 13--> 10 + y = 13--> y = 3OR:3(5) - y = 12--> 15 - y = 12--> y = 3You can then check your values are correct by subsituting them into either of the equations:2(5) + (3) = 1310 + 3 = 13 --> it works!

Answered by Emma W. Maths tutor

10716 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

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


2476 adults watch a cricket match. The ratio men : women is 3 : 1 How many more men than women watch the match?


Factorise the following equation: 2x^2 + 8x + 8


Factorise the following: 21x(squared)-35x


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