Solve the simultaneous equations: 2x-3y = 24 and 6x+2y = -5

There are numerous alternative ways to solve these simultaneous equations. For this problem, one of the simplest methods is to multiply the first equation by 3, so that we get 6x in both equations:

(2x - 3y)3 = 243, giving 6x - 9y = 72

If we now subtract the second equation from the first one (multiplied by 3), we get:

(6x - 9y) - (6x + 2y) = 72-(-5)

This way we are left only with y on the left hand side:

-9y - 2y = 77

-11y = 77

Thus we found the value of y:

y = -77/11 = -7

Now we can substitute the value for y into the first equation and find x (substituting into the 2nd equation would also work fine):

2x - 3(-7) = 24

2x + 21 = 24

2x = 3

x = 3/2

Therefore, the solution is: x = 3/2 and y= -7

Answered by Augustinas S. Maths tutor

2615 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

I am struggling to solve algebra equations. I was given the following equation to solve at school and am unsure how to approach it : 4(x + 3) = 2x + 8


(b) In 2013, the price for each unit of electricity was 13.5 cents. Over the next 3 years, this price increased exponentially at a rate of 8% per year. Calculate the price for each unit of electricity after 3 years


Kenny has £3200 in a savings account. After a year, the bank pays him interest increasing his balance to £3360. What percentage rate was applied to the account?


Calculate the gradient of this straight line


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