Find the value of x and show steps.

4(3x+4)(x-4)

To find the value of x in the expression 4(3x+4)(x-4), first, expand the expression using the distributive property.

4(3x+4)(x-4)
= 4(3x)(x) - 4(3x)(4) + 4(4)(x) - 4(4)(4)
= 12x^2 - 48x + 16x - 64
= 12x^2 - 32x - 64

Now that the expression is expanded, we can simplify it further.

12x^2 - 32x - 64 = 0

Next, we need to solve the quadratic equation for x. To do this, we can either factor the equation or use the quadratic formula.

Factoring:
12x^2 - 32x - 64 = 0
4(3x^2 - 8x - 16) = 0
4(3x + 4)(x - 4) = 0

Setting each factor to zero:
3x + 4 = 0 or x - 4 = 0
3x = -4 x = 4
x = -4/3

Therefore, the two possible values for x are x = -4/3 or x = 4.