4d(2d-9)

8d^2 - 36d

(3x+4)(x-2)

3x^2-6x+4x-8

Simplifying, we get:

3x^2 - 2x - 8

To simplify the expression 4d(2d - 9), we can use the distributive property of multiplication over addition/subtraction.

First, let's distribute the 4d to both terms inside the parentheses:

4d * 2d = 8d^2
4d * (-9) = -36d

Now we can write the simplified expression:

8d^2 - 36d

So, the simplified form of 4d(2d - 9) is 8d^2 - 36d.