Question

find the domain of the following rational expression -7xy^2/28x^5y

Answer 1

the domain is all x values for which the expression is defined, so what you need to ask is: "at what values for x is the expression not defined?"

Answer 2

in the case of rational expressions, the points where it will be undefined are where you attempt to divide by zero, so for what x value(s) does the denominator equal zero?

Answer 3

would the answer be = y^2 5y

Answer 4

to find where the expression is undefined set 28x^5y=0 if you think about it, the x is the only factor that matters because x^(any power) will be a number not equal to zero and so the expression will be defined there, so what value of x makes 28x^5y=0?

Answer 5

\[x=x25y\]

Answer 6

idk

Answer 7

i am not rying to sound like a dummy but algebra is one of my weak subjects im suffering

Answer 8

hello

Answer 9

you do not need to worry about the y in this case because no value of y will make the denominator zero so what value of x will make the denominator zero? you want a number not another expression

Answer 10

4

Answer 11

think about the zero property

Answer 12

is (-7xy^2)/(28x^(5y)) your whole expression?

Answer 13

yes

Answer 14

okay so ignore the ^5y what would you have to multiply 28 by to get zero?

Answer 15

0

Answer 16

exactly, so if you substitute zero in for x you get \[\frac{ -7(0)y^2 }{ 28(0)^5y }\] which means the numerator and denominator are both zero when x is zero. when this happens it creates a "hole" in the graph of the expression or function which means it is discontinuous and not defined there, in this case the expression is defined for all x except 0

Answer 17

so what x=0

Answer 18

i meant to say so the domain is x=0

Answer 19

the domain would be \[{ R, x \neq 0 }\]

Answer 20

all real numbers except zero

Answer 21

so the answer is x -0

Answer 22

x=0

Answer 23

the domain is the set of all x values for which an expression is defined, this expression is not defined at x = 0 so the answer is \[x \neq 0\] and not x = 0

Answer 24

what is the name of that sign youre using

Answer 25

not equal to