Solve the simultaneous equations: 3x +4y = 18, and 5x - 2y = 4

First of all, you would label the equations, so let's call 3x +4y = 18 equation A, and 5x - 2y = 4 equation B. Then you would try to find a way to eliminate one of the variables (either x or y). We can do this by multiplying equation B by 2. Therefore the new equation 2B would equal 10x -4y = 8. We can then eliminate the variable 'y' by adding equation A and 2B together. We would add each individual component, therefore the 'xs' would add together to make (3x+10x) 13x, the 'ys' would add together to make (4x-4x) 0, and the integers would add together to make (18 +8) 26. You would then have the equation 13x = 26 which can then be solved for x (dividing both sides of the equation by 13) to get x = 2. This value for x can then be subbed into either equation A or B in order to find the value of y. Therefore subbing into equation A would give 3(2) + 4y = 18, which rearranging and solving would give a value of y = 3. You can then check your results by subbing both x and y values into the other equation, and seeing if the equation works: 5(2) - 2(3) = 4, which does indeed satisfy the equation. Therefore x = 2 and y = 3

RS
Answered by Rob S. Maths tutor

11353 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

A)Write x^2 – 8x + 25 in the form (x – a)^ 2 + b. (B) Write down the coordinates of the turning point of the graph of y = x2 – 8x + 25. (C)Hence describe the single transformation which maps the graph of y = x2 onto the graph of y = x2 – 8x + 25.


In one month, Karen takes the bus to school on 25 days. On 5 of these days the bus is late. What fraction of the days Karen takes the bus to school is the bus late? (Give your answer in the simplest form)


You are given a square which you are told has a total area of 100 squared centimetres. You are also told that one side of the square has dimension 4(3x + 2), and the other has dimension 8x - y. What are the values of x and y?


If an equation of a line is y=2x+4 and it crosses the x axis at point R, what is the value of x?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning