f(x) = 2x + 18
g(x) = 4x + 6
At what input would both functions produce the same output?
So f and g are inputs and the x in brackets is the output?
2x + 18 = 4x + 6
4x - 2x = 18 - 6
2x = 12
X = 6
Guitar: Jackson JS30KV
PSN id : craig_241
Steam
Quote by Craig_241
2x + 18 = 4x + 6
4x - 2x = 18 - 6
2x = 12
X = 6

Win.
Thanks Craig, I totally forgot thats how you solve that type of problem.
To be honest this is quite basic stuff.
Guitar: Jackson JS30KV
PSN id : craig_241
Steam
Quote by Craig_241
2x + 18 = 4x + 6
4x - 2x = 18 - 6
2x = 12
X = 6

Sorry to be a newb, could you please explain to me the steps to do this and why you do them?
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x=6 if ure confused trial error ftw!
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Quote by DigUpHerBones
Sorry to be a newb, could you please explain to me the steps to do this and why you do them?

You want the functions to be the same yes? So you make them equal to each other. Then solve the simple equation.
Guitar: Jackson JS30KV
PSN id : craig_241
Steam
Quote by DigUpHerBones
Sorry to be a newb, could you please explain to me the steps to do this and why you do them?

Simultaneous equations. You want to find a point both lines go through.
f(x)=y
g(x)=y
f(x)=g(x)

You make them equal, then solve the equation.
This can be done with any equations as long as the subject is the same. Other methods involve substitution.
Quote by Renka
OddOneOut is an Essex S&M mistress and not a pirate or a computer program.

well my mindset at the time was "sick, math work..."
instead of "oh common sense, they are equal to each other so just set them equal to each other and solve for x"
Quote by Craig_241
You want the functions to be the same yes? So you make them equal to each other. Then solve the simple equation.

Quote by OddOneOut
Simultaneous equations. You want to find a point both lines go through.
f(x)=y
g(x)=y
f(x)=g(x)

You make them equal, then solve the equation.
This can be done with any equations as long as the subject is the same. Other methods involve substitution.

Thankyou . My brain is being incredibly slow today!
There's only one thing we can do to thwart the plot of these albino shape-shifting lizard BITCHES!
Quote by OddOneOut
Simultaneous equations. You want to find a point both lines go through.
f(x)=y
g(x)=y
f(x)=g(x)

You make them equal, then solve the equation.
This can be done with any equations as long as the subject is the same. Other methods involve substitution.

If he doesn't know how to equate two equations together, there is no point bringing in simultaneous equations into this.
Guitar: Jackson JS30KV
PSN id : craig_241
Steam
Quote by Craig_241
Simultaneous equations. You want to find a point both lines go through.
f(x)=y
g(x)=y
f(x)=g(x)

You make them equal, then solve the equation.
This can be done with any equations as long as the subject is the same. Other methods involve substitution.

If he doesn't know how to equate two equations together, there is no point bringing in simultaneous equations into this.

Goddamn. I'm tired, okay? I can do some simultaneous equations and I've been able to do this in better states of mind!
There's only one thing we can do to thwart the plot of these albino shape-shifting lizard BITCHES!
Quote by Craig_241
If he doesn't know how to equate two equations together, there is no point bringing in simultaneous equations into this.

Best to know what it's called. The question could've asked to 'solve these equations simultaneously'

No problem Katherine, did them in my exam today, but using trig identities and substitution
Quote by Renka
OddOneOut is an Essex S&M mistress and not a pirate or a computer program.

Quote by OddOneOut
Best to know what it's called. The question could've asked to 'solve these equations simultaneously'

No problem Katherine, did them in my exam today, but using trig identities and substitution

Fairy nuft! Thanks
I've decided to get an A, at least, in maths (haha at me) so I'm going to (need to) put a lot of work in to it.
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Yay, Algebra.

This should be "the ONLY homework help thread". Lol.

Mainly because the new section we've been introduced to today in math completely goes right over me. xD

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Quote by xJawsh
f(x) = 2x + 18
g(x) = 4x + 6
At what input would both functions produce the same output?

hi my name's paul and i got a A for grade 11 maths last year so i thought i would say some stuff on the simultaneous equations.

Input value:any number that is substituted into a given equation
Output:the result of a specific imput value substituted into a equation
functions: a relationship between two variables(namely x and y in this case)

the straight line equation is given as y=ax+c,in the equation you have 3 terms(peices of information seperated by a + or a -). Simultaneous equations are the solving of two given equations at the same time. You can begin by writing out the two given equations as follows and making one of the terms in each of the equations equall to the corresponding term(i.e ax) in the other equation,i'll use x's just because it's a different method:

g(x)=y=4x+6
f(x)=4x+36(x2,to get the ax's equall)
therefore:
(1)4x=y-6(g(x) with ax as the subject)
(2)4x=2y-36(likewise for f(x))
solve:
y-6=2y-36(1=2)
-y=-30
y=30
but you are looking for a imput value(x),the output is going to be(y) so solve for x with either of the equations:
g(x)=y=30=4x+6
24=4x
therefore x=6,XER(x is a element of all numbers besides imaginary numbers(-roots))

if you need any help with other problems feel free to pm me