How do you factor a^2b+6ab^2+9b^2a2b+6ab2+9b2?

1 Answer
Jan 18, 2017

See solution below

Explanation:

To factor this, because all terms are positive and there are two variables we know the factoring will be in the form:

(color(red)(j)a + color(blue)(k)b)(color(green)(l)a + color(purple)(m)b)(ja+kb)(la+mb)

Where color(red)(j)j, color(blue)(k)k, color(green)(l)l and color(purple)(m)m are constants.

We also know because of the coefficients in the original problem:
color(red)(j) xx color(green)(l) = 1j×l=1
color(blue)(k) xx color(purple)(m) = 9k×m=9
(color(red)(j) xx color(purple)(m)) + (color(blue)(k) xx color(green)(l)) = 6(j×m)+(k×l)=6

"Playing" with the factors for 99 (1x9, 3x3, 9x1) Gives:

(color(red)(1)a + color(blue)(3)b)(color(green)(1)a + color(purple)(3)b)(1a+3b)(1a+3b)

(a + 3b)(a + 3b) = (a + 3b)^2(a+3b)(a+3b)=(a+3b)2