# Linear Equation Q3

• March 6th 2009, 01:48 AM
mj.alawami
Linear Equation Q3
Question
$\frac{3x^2+4}{x^3+8}=\frac{3}{x+2}$

Attempt:

$3x^3+6x^2+4x+8=3x^3+24$

Final answer I got is 2

Thank you
• March 6th 2009, 01:59 AM
Quote:

Originally Posted by mj.alawami
Question
$\frac{3x^2+4}{x^3+8}=\frac{3}{x+2}$

Attempt:

$3x^3+6x^2+4x+8=3x^3+24$

Final answer I got is 2

Thank you

$3x^3+6x^2+4x+8=3x^3+24$
$6x^2 +4x-16=0$

$3x^2 + 2x-8=0
$

$3x^2 + 6x-4x-8=0$

$3x(x+2)-4(x+2)=0$

$(3x-4)(x+2)=0$

x=4/3 or x=(-2)

But -2 is not allowed as denominator can't be 0