Answer:
9x^2 + 21x + 12
Step-by-step explanation:
(3x+4)(x+2x+3)
Combine x and 2x to get 3x.
(3x+4)(3x+3)
Apply the distributive property by multiplying each term of 3x+4 by each term of 3x+3.
9x^2 + 9x + 12x + 12
Combine 9x and 12x to get 21x.
9x^2 + 21x + 12
