Question

1. n + m - n(m + n); use m = -1, and n = 4

Explanation:

Step1: Substitute given values

Substitute $m=-1$, $n=4$ into the expression:
$4 + (-1) - 4\times(-1 + 4)$

Step2: Simplify parentheses first

Calculate the sum inside the parentheses:
$4 - 1 - 4\times(3)$

Step3: Perform multiplication

Carry out the multiplication operation:
$4 - 1 - 12$

Step4: Compute final subtraction

Calculate the left-to-right subtraction:
$3 - 12 = -9$

Answer:

$-9$