Intermediate Algebra

[jamjam]

Factor and state if prime: 4a^3 + 12a^2 - 72a; Help!


Factor and state if prime:I came up with;
2^2 + 3xa + 6x + 18a
x * 6x = 6x^2
x * 3a = 3xa
6 * 3a = 18a
(x + 6)(x + 3a)
x * x = x^2
x * 3a = 3xa
6 * x = 6x
6 * 3a = 18a
(x + 6)(x + 3a)
x * x = x^2
x * 3a = 3xa
6 * x = 6x
6 * 3a = 18a

 

[masters]

Factor and state if prime: 4a^3 + 12a^2 - 72a; Help!


Factor and state if prime:I came up with;
2^2 + 3xa + 6x + 18a
x * 6x = 6x^2
x * 3a = 3xa
6 * 3a = 18a
(x + 6)(x + 3a)
x * x = x^2
x * 3a = 3xa
6 * x = 6x
6 * 3a = 18a
(x + 6)(x + 3a)
x * x = x^2
x * 3a = 3xa
6 * x = 6x
6 * 3a = 18a

Hi jamjam.

Wow! What is all that stuff?

Factor: \(\displaystyle 4a^3+12a^2-72a\)

First, look for a common monomial factor. Found it..\(\displaystyle 4a\)

\(\displaystyle 4a(a^2+3a-18)\)

Now, look to see if you can factor the trinomial. Can you come up with two factors of -18 that will add to +3? Found them...+6 and -3

\(\displaystyle 4a(a+6)(a-3)\)

Done!

 

[garf]

Hi!
Just remember that factor a number (or expression) means find a set of mathematical expressions (or numbers) that multiplied together give you the original number or expression
garf