What is the value of the expression below when z=5? 4z^{2}-7z-2

To find the value of the expression \( 4 z^{2}-7 z-2 \) when \( z=5 \), we substitute \( z \) with \( 5 \): \[ 4(5)^{2} - 7(5) - 2 \] Calculating \( 5^2 \): \[ 5^2 = 25 \] Now substituting this back into the expression: \[ 4(25) - 7(5) - 2 \] Calculating \( 4(25) \): \[ 4 \times 25 = 100 \] Calculating \( 7(5) \): \[ 7 \times 5 = 35 \] Now substituting these values back: \[ 100 - 35 - 2 \] Now performing the subtraction: \[ 100 - 35 = 65 \] Now subtract \( 2 \): \[ 65 - 2 = 63 \] Thus, the value of the expression when \( z=5 \) is \(\boxed{63}\).