What is (3x-4) (7x+4)

Answer:21x^2-16x-16

Step-by-step explanation:

(3x) (7x) + (3x) (4) + (-4) (7x) + (-4) (4) =

21x^2+12x-28x-16

21x^2-16x-16

21x^2 - 16x - 16

Step-by-step explanation:

This is a basic multiplication question,

We all know that (a+b) (c+d) = ac+ad+bc+bd

Here,

a = 3x

b = - 4

c = 7x

d = 4

Therefore,

3x*7x + 3x*4 + (-4) * 7x + (-4) * 4

=> 21x^2 + 12x - 28x - 16

=> 21x^2 - 16x - 16