Solve this for me

Please show how you worked it out.

X + y = 7

X(2) +y (2) = 25

Now I know x squared + y squared are 3 and 4 respectively but I got there by trial and error.

What’s x?

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X = 7-y

(7-y) (2) + y(2) = 25

y(2) = 25 - (7-y)(2)

No idea kid.

Is the two supposed to be squared?

Yep

x could be 3 or it could be 4?

x =7 - y

(7-y)(7-y) + y(y) = 25
49 -14y + 2y(y) = 25

2y(2) -14y +24 = 0

y(2) - 7y + 12 = 0

(y-3) (y-4) = 0

y = 3 or 4
x = 3 or 4

It’s been a long time since I’ve done it, but I’m pretty sure that’s right.

6 Likes

Yeah it’s the young one doing some revision

Algebra & stats were the sections of maths that I was actually pretty handy at. And while it’s been a while since I’ve regularly done quadratics, it’s probably slight less time than most others here :joy:

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Ah fuck it lad, I’ve been spending the last hour looking for common denominators, squaring things and even factoring by 3 trying to figure it out. Burnt the fucking dinner in the mean time

Spot on kid. And top marks for showing your work as well.

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I was just coming in to post, I’ve bad news for you Mike there’s two answers :joy:

Go on…

The lad has em above, 3,4 and 3,4

I might be wrong but that seems like a very convoluted solution

It’s Leaving Cert maths, it’s supposed to be convoluted.

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You could short cut it in your head but they are all the steps you’d have to take on the way to that point. And you need to show your work in case you make a balls of it

He was going grand for a while. But you shouldn’t end up with two answers.