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paulb203

Member

Registered: 2023-02-24

Posts: 136

x^2-9y^2=0 (where x>0 and Y>0) Work out the ratio x:y

x^2-9y^2=0 (where x>0 and Y>0)
Work out the ratio x:y

Not sure where to start with this one.

Take -9y^ from both sides? Not sure if that achieves anything.
x^2 = -9y^2

Square root of both sides?
What’s the square root of –9y^2?

Tough one...

EDIT;

If I take -9y^2 from both sides it should then be:

x^2 = 9y^2

As for the square root of 9y^2..?

That is 3y, yeah?

So if I square root both sides I get:

x=3y?

Last edited by paulb203 (2023-10-19 19:13:58)

Bob

Administrator

Registered: 2010-06-20

Posts: 10,196

Re: x^2-9y^2=0 (where x>0 and Y>0) Work out the ratio x:y

Yes but make that  ±

edit: Sorry, cancel that as you're told x > 0 y > 0

Answer good as it stands, but put it as a ratio as asked.

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

amnkb

Member

Registered: 2023-09-19

Posts: 253

Re: x^2-9y^2=0 (where x>0 and Y>0) Work out the ratio x:y

x^2-9y^2=0 (where x>0 and Y>0)
Work out the ratio x:y

Not sure where to start with this one.

factor the difference of squares

since x and y have to be positive then

create ratio

substitute for x
simplify