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Let $p$ and $q$ be the two distinct solutions to the equation $(x-3)(x+3) = 21x - 63.$
If $p > q$, what is the value of $p - q$?

Respuesta :

Given:

p and q are the two distinct solutions to the equation

[tex](x-3)(x+3)=21x-63[/tex]

To find:

The value of p-q if p>q.

Solution:

We have,

[tex](x-3)(x+3)=21x-63[/tex]

[tex](x-3)(x+3)=21(x-3)[/tex]

[tex](x-3)(x+3)-21(x-3)=0[/tex]

[tex](x-3)(x+3-21)=0[/tex]

[tex](x-3)(x-18)=0[/tex]

Using zero product property, we get

[tex]x-3=0\text{ and }x-18=0[/tex]

[tex]x=3\text{ and }x=18[/tex]

Here, 18>3, so p=18 and q=3.

Now,

[tex]p-q=18-3[/tex]

[tex]p-q=12[/tex]

Therefore, the value of p-q is 12.