How do you multiply #(4c+9d)^2#?

1 Answer
Aug 13, 2017

See a solution process below:

Explanation:

We can use this rule for multiplication to multiply the expression:

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

Substituting #color(red)(4c)# for #color(red)(x)# and #color(blue)(9d)# for #color(blue)(y)# gives:

#(color(red)(4c) + color(blue)(9d))^2 => (color(red)(4c))^2 + (2 * color(red)(4c) * color(blue)(9d)) + (color(blue)(9d))^2 =>#

#16c^2 + 72cd + 81d^2#