Solve the simultaneous equations: 4x+3y=5 and x-y=3, to find the values of x and y.

First of all, we need to get the equations in a form so that either x or y can be eliminated.

In this case, I have a positive amount of y, and a negative amount of y, meaning that I can add the two equations together, once I have made my amounts of y equal. To do this, I will multiply the second equation by 3 to give: 3x-3y=9. When I add this to the first equation I get (4x+3x)+(3y-3y)=(5+9), as when I add a negative number, this is the same as subtraction. So I get 7x=14, which dividing both sides by 7 gives x=2.

However, the question also requires me to find a value for y, so I substite my new value of x into the second equation of the question, so 2-y=3, therefore y=2-3, which gives y=-1.

Therefore we have x=2 and y=-1 as our answer.

LP
Answered by Laura P. Maths tutor

10650 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

There is a right angled triangle, you know the length of the hypotenuse (6) and one other side (3), can you calculate the third side of the triangle?


What's the difference between the mean, median and mode?


Solve the inequality x^2+2x-8<0


Solve the equation x^2 + 10x + 24 = 0


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