Question

1. $(-4) - (-9) cdot (-4) - {(-4) + (-9)}$

Explanation:

Step1: Innermost parentheses first

Calculate $(-4) + (-9) = -13$

Step2: Simplify curly braces

Calculate $(-4) - (-13) = -4 + 13 = 9$

Step3: Multiply by outer term

Calculate $(-9) \cdot 9 = -81$

Step4: Final subtraction

Calculate $(-4) - (-81) = -4 + 81$

Answer:

77