restrictions

G

Guest

Guest
I forget how you're suppose to do restrictions for an equation like this:

(x^2-x-6)/ (x-3)

= (x-3)(x+2)/(x-3)

= x+2, restrictions : x can not equal 3

I get how you do (x-3)=0, therefore equals 3, but how come its not done to the (x+2) as well? do you only do it to the numbers you cancel out?

-Anna
 
Hello, anna!

The restriction applies to values of x which make the <u>denominator</u> zero.
. . We don't care what the numerator becomes, you see.

Even if there is no cancelling . . . like: . x(x - 3) / (x - 1)(x + 2)

. . the restrictions are: . x ≠ 1, .x ≠ -2
 
ahh ok thanks..so its only the denominator ! kk I get it now ^^ thanks
 
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