C1 Maths Surds in Simultaneous Equations Help!

I've started C1 for my A-Level this year and I'm doing surds at the moment. I've grasped the topic well but for my homework, I've got to do this simultaneous equation that I'm stuck on. I've been on it for almost an hour now with no progress whatsoever. Any help would be appreciated.

xsqrt5 + 2y = 3

x + y = 1

I've tried substituting x and y into the top equation but nothing has come out of it for me.

Original post by AndINeedHelp

I've started C1 for my A-Level this year and I'm doing surds at the moment. I've grasped the topic well but for my homework, I've got to do this simultaneous equation that I'm stuck on. I've been on it for almost an hour now with no progress whatsoever. Any help would be appreciated.

xsqrt5 + 2y = 3

x + y = 1

I've tried substituting x and y into the top equation but nothing has come out of it for me.

Show your working.

Reply 2

Zacken

22

Original post by AndINeedHelp

I've started C1 for my A-Level this year and I'm doing surds at the moment. [...] I've tried substituting x and y into the top equation but nothing has come out of it for me.

It's the same as any other simultaneous equation, the second one re-arranges to

y = 1-x

which you can then plug into the first equation to get an equation solely in

x

and then solve for it.

Reply 3

AndINeedHelp

OP

Original post by RDKGames

Show your working.

So I rearrange the second equation into y = 1 - x

From that, I get x sqrt 5 + 2 - 2x = 3 and xsqrt5 - 2x = 1

I've absolutely no clue where to go from here.

Original post by AndINeedHelp

So I rearrange the second equation into y = 1 - x

From that, I get x sqrt 5 + 2 - 2x = 3 and xsqrt5 - 2x = 1

I've absolutely no clue where to go from here.

Move the +2 over to the RHS and factor out the x.

Reply 5

AndINeedHelp

OP

Original post by Guinnie

you can't solve the simultaneous equaitons without a calculator

Well, that's not true because we're expected to solve this without one.

Reply 6

k.russell

13

Original post by Guinnie

you can't solve the simultaneous equaitons without a calculator

say whaaaaatttt? you deffo can lol

Reply 7

AndINeedHelp

OP

Original post by RDKGames

Move the +2 over to the RHS and factor out the x.

xsqrt5 - 2x = 1

I honestly don't know I can work out x from this.

Reply 8

k.russell

13

Original post by AndINeedHelp

Well, that's not true because we're expected to solve this without one.

The method is to get all the x's together on one side and everything else on t'other, then pick out a factor of x. You should be able to solve from there, right?