I need help simplifying an expression that is in this form: (3x + 12) / (9x^2 - 144) thanks in advanced.
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Originally Posted by jenbones I need help simplifying an expression that is in this form: (3x + 12) / (9x^2 - 144) thanks in advanced. Hint: $\displaystyle 9x^2-144= (3x)^2-(12)^2$ Do you know how to factor this?
No, I am not very good at factoring.
Originally Posted by jenbones No, I am not very good at factoring. Remember the difference of squares formula? $\displaystyle a^2-b^2=(a+b)(a-b)$
yes, I remember that formula.
Originally Posted by jenbones yes, I remember that formula. Utilising it will allow you to simplify by cancelling the numerator with one of the factors.
Originally Posted by jenbones I need help simplifying an expression that is in this form: (3x + 12) / (9x^2 - 144) thanks in advanced. $\displaystyle \frac{3x + 12}{9x^2 - 144} = \frac{3x + 12}{(3x+12)(3x-12)} = \frac{1}{3x-12}$
Originally Posted by yehoram $\displaystyle \frac{3x + 12}{9x^2 - 144} = \frac{3x + 12}{(3x+12)(3x-12)} = \frac{1}{3x-12}$ isn't the answer (1) / (3 (x - 4)) ??
Originally Posted by jenbones isn't the answer (1) / (3 (x - 4)) ?? Yes... $\displaystyle \displaystyle\frac{1}{3x-12}=\frac{1}{3(x)-3(4)}=\frac{1}{3(x)+3(-4)}=\frac{1}{3(x-4)}$