help pls.

Question

simplify, whats the non permissible and the show how to check the answer.

b)  4x-1 over x²+7x+12 Divided by 2x-6 over x²+x-12

Answer 1

b)

The given expression is

Find the factorization:

x² + 7x + 12 = x² + 4x +3x + 12 = x(x+4)+3(x+4) = (x+4)(x+3)

x² + x - 12 = x² + 4x -3x - 12 = x(x+4)-3(x+4) = (x+4)(x-3)

 

Checking of the the answer :

Substitute test value x = 1

Both sides are equal. So answer is verified.

Comments

Is there any non permissible?

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Non permissible value : It is the value of the variable in the rational expression that which makes the rational expression undefined.To find Non permissible value make denominator equals to zero.

2 ( x + 3 ) = 0

x + 3 = 0

x = - 3.

Here only one non permissible value exists, that is x = - 3.

Checking of the the Non permissible value  :

Substitute non permissible value x = - 3 in the given expression.

So non permissible value is verified.