Help me please (x^2 + 2x)/(12x + 54) - (3 - x)/(8x +36)
Hello, your first step is to factor the expression. Can you do that for me, hun?
wait first aren't you supposed to turn the subtraction sign into an addition sign... and you do that by multiplying it by -1 and it only effects the numerator
No - your first step is simplifying.
I actually have to go! Sorry! But I bet @ganeshie8 or @goformit100 can assist you! :)
x(x + 2)/ 6(2x + 9) - (-3 + x)/4(2x + 9)?
you mean x(x + 2)/ 6(2x + 9) + (-3 + x)/4(2x + 9)?
\(\large \frac{x(x + 2)}{ 6(2x + 9)} + \frac{(-3 + x)}{4(2x + 9)} \)
oops ya sorry.. and now I know we're supposed to have a common denominator
yes, so how to get a common denominator ?
wats lcm of 6 and 4 ?
is it 12 ?
You multiply 4 to the numerator and the denominator of the first fraction and multiply 6 to the numerator and the denominator of the 2nd fraction?
perfect !
\(\large \frac{x(x + 2)}{ 6(2x + 9)} + \frac{(-3 + x)}{4(2x + 9)} \) \(\large \frac{4x(x + 2)}{ 24(2x + 9)} + \frac{6(-3 + x)}{24(2x + 9)} \)
now that we have denominators same, simply add numerators
ok that makes sense so far
would you multiply the 6 and the 4x in the numerators
yes
\(\large \frac{x(x + 2)}{ 6(2x + 9)} + \frac{(-3 + x)}{4(2x + 9)} \) \(\large \frac{4x(x + 2)}{ 24(2x + 9)} + \frac{6(-3 + x)}{24(2x + 9)} \) \(\large \frac{4x^2+8x}{ 24(2x + 9)} + \frac{-18 + 6x}{24(2x + 9)} \)
add them now
\(\large \frac{x(x + 2)}{ 6(2x + 9)} + \frac{(-3 + x)}{4(2x + 9)} \) \(\large \frac{4x(x + 2)}{ 24(2x + 9)} + \frac{6(-3 + x)}{24(2x + 9)} \) \(\large \frac{4x^2+8x}{ 24(2x + 9)} + \frac{-18 + 6x}{24(2x + 9)} \) \(\large \frac{4x^2+8x-18+6x}{ 24(2x + 9)} \)
simplify
why wouldn't you just multiply the 6 and 4x and just leave it like 24x(x + 2)(x - 3)
could you do that?
dint get u
for the 4x and 6 you distributed but do you have to do that or can you just combine them like 24x(x +2)(-3 + x)
?
you will have to distribute that
\(\large \frac{x(x + 2)}{ 6(2x + 9)} + \frac{(-3 + x)}{4(2x + 9)} \) \(\large \frac{4x(x + 2)}{ 24(2x + 9)} + \frac{6(-3 + x)}{24(2x + 9)} \) \(\large \frac{4x^2+8x}{ 24(2x + 9)} + \frac{-18 + 6x}{24(2x + 9)} \) \(\large \frac{4x^2+8x-18+6x}{ 24(2x + 9)} \) \(\large \frac{4x^2+14x-18}{ 24(2x + 9)} \) \(\large \frac{2(2x^2+7x-9)}{ 24(2x + 9)} \) \(\large \frac{2x^2+7x-9}{ 12(2x + 9)} \)
we end up like that see if it makes some sense
okay so we HAVE to distribute
yup !
see if u can factor numerator and can cancel something
(2x^2 - 2x)(9x - 9)
\(\large \frac{x(x + 2)}{ 6(2x + 9)} + \frac{(-3 + x)}{4(2x + 9)} \) \(\large \frac{4x(x + 2)}{ 24(2x + 9)} + \frac{6(-3 + x)}{24(2x + 9)} \) \(\large \frac{4x^2+8x}{ 24(2x + 9)} + \frac{-18 + 6x}{24(2x + 9)} \) \(\large \frac{4x^2+8x-18+6x}{ 24(2x + 9)} \) \(\large \frac{4x^2+14x-18}{ 24(2x + 9)} \) \(\large \frac{2(2x^2+7x-9)}{ 24(2x + 9)} \) \(\large \frac{2x^2+7x-9}{ 12(2x + 9)} \) \(\large \frac{(x-1)(2x+9)}{ 12(2x + 9)} \) \(\large \frac{x-1}{ 12} \)
that makes soo much sense thank you =)
np :)
wait
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