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Can someone plz help me get started on these fractions
f(x)=3x8 div 4x+20
 2 years ago
 2 years ago
Can someone plz help me get started on these fractions f(x)=3x8 div 4x+20
 2 years ago
 2 years ago

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saifoo.khanBest ResponseYou've already chosen the best response.0
\[\frac{ 3x  8}{4x + 20}\to \frac{3x8}{4(x+5)}\]As there is nothing common between denominator and numerator so we cannot simply it.
 2 years ago

denise9423Best ResponseYou've already chosen the best response.0
sorry I just found this.
 2 years ago

denise9423Best ResponseYou've already chosen the best response.0
How do I find the domain
 2 years ago

Akshay_BudhkarBest ResponseYou've already chosen the best response.2
domain is all real numbers except for 5
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
No division by zero. So what is x going to be when the denominator is zero?
 2 years ago

saifoo.khanBest ResponseYou've already chosen the best response.0
set the denominator equal to zero right? @Akshay_Budhkar
 2 years ago

denise9423Best ResponseYou've already chosen the best response.0
f(x)=3x8 over 4x+20
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
@denise9423 Domain means all of the values x can take on. Here's your domain: \[x \neq5\]
 2 years ago

Akshay_BudhkarBest ResponseYou've already chosen the best response.2
If you have a look the function is having real values for all values except for x=5 when it is not defined as the denominator is zero
 2 years ago

denise9423Best ResponseYou've already chosen the best response.0
can you show me how to get 5
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
4x+20 =0 Solve for x. x=5.
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
Do you know why division by zero is not allowed?
 2 years ago

denise9423Best ResponseYou've already chosen the best response.0
ok,then can i sub it also 3x8
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
you only need to worry about the bottom.
 2 years ago

denise9423Best ResponseYou've already chosen the best response.0
no to ur question ok
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
Remember this: What is 1 divided by 0? In other words, what times zero can equal 1? 0*2? 0*3? There is nothing you can multiply by zero to get 1. So whenever you get these fractions and they ask you to find the domain, just think about what x has to be in order for the denominator to equal zero.
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
If you have an equation in the denominator, then set that equal to zero :)
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
Or if you have 1/(x^2+2x+3) . If you have something weird like that, then set it equal to zero and use the quadratic formula to solve for your two xvalues. Those xvalues are what x can't equal. Sorry, I sound like I'm talking in riddles lol.
 2 years ago

denise9423Best ResponseYou've already chosen the best response.0
ok so 7xyy over 28xxxxxy=0
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
I'm gonna be more specific with what I said, sorry my fault: Or if you have 1/(x^2+2x+3) . If you have something weird like that, then set it equal to zero and use the quadratic formula to solve for your two xvalues. Those xvalues are what x can't equal. Sorry, I sound like I'm talking in riddles lol. x^2+2x+3 = 0 (then use the quadratic formula and solve for x)
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
I don't think they'll ask you to find the domain of something with x's and y's. Or are they?
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
I can help you on something like that, but first off is that denominator stuff making sense? Really sleep on that and try to remember it b/c it's super important for calculus.
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
Okay well what multiples to 7 and 8 have in common? What can you divide them both by?
 2 years ago

denise9423Best ResponseYou've already chosen the best response.0
yes it does bc it will help me remember to put=0 so I can solve for x
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
7xyy/28xxxxxy You can divide the numerator and denominator by 7. Also, which has the smallest amount of x's, and then which one has the smallest amount of y's?
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
The numerator has the smallest amount of x's. There is 1 of them. The denominator has the smallest amount of y's, which is 1 y. So we'll divide the numerator and denominator by 7. 1*x*y*y/4xxxxxy
 2 years ago

denise9423Best ResponseYou've already chosen the best response.0
bottom has 5 x's and the top has 2 y's
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
We have to cancel out the smallest amount of x's. And we also cancel out the smallest amount of y's. So we have: 1*y/4xxxx I canceled out an x on the top and bottom. Then I canceled out a y on the top and bottom.
 2 years ago

denise9423Best ResponseYou've already chosen the best response.0
sorry i have a 911 gotta chk out b back later thank you for all ur help god bless
 2 years ago

brinetheryBest ResponseYou've already chosen the best response.4
Anyway, 1*y/4xxxx can be rewritten as: y/4x^4 See Paul, my favorite math teacher: (I swear by his notes) http://tutorial.math.lamar.edu/Classes/Alg/IntegerExponents.aspx
 2 years ago
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