Question

Find the LCM (7+3x),(49-9x^2),(7-3x)

Answer 1

notice that the middle expression is the product of the other two:
(7+3x)*(7-3x) = 49-9x^2

so your answer should be...

Answer 2

We have
\[(7+3x), (49-9x^2), (7-3x)\]
LCM =
\[(the\ common\ factor\ \times the\ uncommon\ factors)\]
Let's factor\( (49-9x^2)\)
We know that
\[a^2-b^2=(a+b)(a-b)\]
so
\[49-9x^2=(7+3x)(7-3x)\]
so
We have
\[7+3x, (7+3x)(7-3x), (7-3x)\]
Let's find the LCM of the first two terms
Common Factor= (7+3x)
Uncommon Factor for first = none
Uncommon factor for second term= (7-3x)
So LCM is \[(7+3x) \times(7-3x)\]

Now take LCM of \((7+3x) \times(7-3x)\) and (7-3x)
Common factor = 7-3x
Uncommon for first= 7+3x
Uncommon for second = none
so
\[LCM\ is= (7+3x)(7-3x)\]

Answer 3

impressive...
try thinking about your problem this way...
What's the LCM of 2,6,3? Since 2*3=6, LCM must be 6.

Answer 4

Which is equal to 21x(x+3)(x+7)