Please help! I have tried everything.

wwdawg

New member
Joined
Apr 12, 2021
Messages
1
"For what value of m is the following rational equation undefined"
m - 8/m = - 4

the answer must be an equation. What even? I'm so confused!
 

Dr.Peterson

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Nov 12, 2017
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11,311
"For what value of m is the following rational equation undefined"
m - 8/m = - 4

the answer must be an equation. What even? I'm so confused!
The answer will have the form "m = something".

Suppose I gave you a value for m, and you tried evaluating your expression. In what one case would you say, "I can't do it"? That will be the number they are asking for.

What number can't you divide by?
 

lev888

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Joined
Jan 16, 2018
Messages
2,078
"For what value of m is the following rational equation undefined"
m - 8/m = - 4

the answer must be an equation. What even? I'm so confused!
Typo? Should be `(m-8)/(m-4)`? But then this is an expression, not an equation. And the answer is a value, not an equation either.
 

Subhotosh Khan

Super Moderator
Staff member
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Messages
24,403
"For what value of m is the following rational equation undefined"
m - 8/m = - 4

the answer must be an equation. What even? I'm so confused!
Is the given rational equation:

\(\displaystyle m - \frac{8}{m} \ = -4\)

or

\(\displaystyle \frac{m - 8}{m} \ = -4\)

Please clarify!
 

HallsofIvy

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Joined
Jan 27, 2012
Messages
7,464
If the equation is m- 8/m= -4 then clearly m cannot be 0. Multiplying both sides by m gives m^2- 8= -4m or
m^2+ 4m- 8= 0. That is a quadratic equation that can be solved by completing the square or using the quadratic formula.

If, as Subhotosh Kahn suggested, you meant (m- 8)/m= -4 (m- 8/m would be bad notation here but many people make that mistake) then multiplying both sides by m, m- 8= -4m which reduces to 5m= 8.
 

lev888

Senior Member
Joined
Jan 16, 2018
Messages
2,078
If the equation is m- 8/m= -4 then clearly m cannot be 0. Multiplying both sides by m gives m^2- 8= -4m or
m^2+ 4m- 8= 0. That is a quadratic equation that can be solved by completing the square or using the quadratic formula.

If, as Subhotosh Kahn suggested, you meant (m- 8)/m= -4 (m- 8/m would be bad notation here but many people make that mistake) then multiplying both sides by m, m- 8= -4m which reduces to 5m= 8.
I doubt this is supposed to be an equation. What does it mean "the following rational equation is undefined"? An equation either has solutions or it doesn't. I've never heard an equation characterized as defined or undefined.
 
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