The Student Room Group

maths hw help

im stuck on this question:
solve the simultaneous equations.
2x+3y = 10
3x+5y = 17
Original post by hurtinguser
im stuck on this question:
solve the simultaneous equations.
2x+3y = 10
3x+5y = 17

I think a good first step would be to multiply the first equation by 3 and the second equation by 2 so your coefficients of x are the same. Does that help set you off on the right path?
Original post by GiftedDipstick
I think a good first step would be to multiply the first equation by 3 and the second equation by 2 so your coefficients of x are the same. Does that help set you off on the right path?

yes thank you
(edited 1 year ago)
Reply 3
Original post by hurtinguser
im stuck on this question:
solve the simultaneous equations.
2x+3y = 10
3x+5y = 17

You can do as the other poster suggested, or rearrange one of the equations to write y in terms of x (or vice versa) and then substitute into the other equation.

I'm guessing these are the 2 methods that you're most likely to be familiar with.
Original post by davros
You can do as the other poster suggested, or rearrange one of the equations to write y in terms of x (or vice versa) and then substitute into the other equation.

I'm guessing these are the 2 methods that you're most likely to be familiar with.

i think there's the subtracting or adding method but im not sure whether i should add or subtract
Reply 5
Original post by hurtinguser
i think there's the subtracting or adding method but im not sure whether i should add or subtract

I think you're referring to what the other poster was saying - if you multiply your equations by suitable numbers, you can make the x-coefficients the same. You can then subtract one equation from the other to eliminate x. If you had coefficients that were the same but of opposite sign, for example 3x and -3x, then you could add the two equations together to eliminate x :smile:

Quick Reply

Latest