Subt. Poly & Bi x Bi Guided

My Try Problem #1
What is the coefficient (number in front) of the middle/z-term in the final answer for: $\left(3z^2+4z\ -3\right)\ -\ \left(2z^2-6z+7\right)$

My Try Problem #2
What is the value of the constant (regular number, no variable/letter) of the in the final answer for: $(2x^2-2x+3)−(\ -4x+5-3x^2)$

My Try Problem #3
What is the value of the constant (regular number, no variable/letter) of the in the final answer for: $\left(2x+3\right)\left(x+4\right)$

My Try Problem #4
What is the coefficient (number in front) of the middle/x-term in the final answer for: $\left(x-3\right)\left(4x-5\right)$