How do you find the product #(3a^2+7b)(3a^2-7b)#?

1 Answer
Aug 29, 2017

Answer:

See a solution process below:

Explanation:

This is a special case quadratic:

#(color(red)(x) + color(blue)(y))(color(red)(x) - color(blue)(y)) = color(red)(x)^2 - color(blue)(y)^2#

Let #color(red)(x) = color(red)(3a^2)# and let #color(blue)(b) = color(blue)(-7b)#

Substituting gives:

#(color(red)(3a^2) + color(blue)(-7b))(color(red)(3a^2) - color(blue)(-7b)) = color(red)((3a^2))^2 - color(blue)((-7b))^2 = 9a^4 - 49b^2#