Math help: Functions

[Mixah]

y=9/5x+32........... i have to find out at which number, x and y are equal

I forget how to do functions so badly..........

[Septimus Prime]

By 9/5x, do you mean (9/5)x or 9/(5x)? It makes a pretty big difference.

[Mixah]

9/5 x as in 1.8x where 1.8 is the slope and 32 is the y intersect.

[Septimus Prime]

Assume y=x and solve. So now you solve for y=(9/5)y+32.

[Mixah]

ok....... y-32 = 1.8y
now what? i already went there, and i got stuck....

this is the conversion from Celsius to Farenheit. I know the answer is -40, but I know that for fact from physics... I have no idea how to get them to be equal though, because not every problem I come across will have them as equals

[SaikyoticAlx]

You want to have it so that y appears on one side of the equation by subtracting y from both sides, i.e.

y-32 = 1.8y

Subtracting y from both sides (y - 32 - y = 1.8y - y)
gives you

-32 = 0.8y

Then dividing both sides by 0.8 gives you -40.

[Mixah]

Since x=y, substitute y for x (or vice-versa), i.e.,

y=(9/5)y+32

-(4/5)y = 32

y = -40 = x

Thanks... I haven't done math in a while, so I forgot that when you have y-9/5y, you get -4/5y... so that's where my biggest problem was...

really appriciated. :)

[Chozen1]

here:

y=mx+b

[Mixah]

here:

y=mx+b
THANK YOU FOR BEING 100% USELESS!