Chapter 4.9, Problem 1MRE

To determine

To simplify: the given numerical expression and find its value

Answer to Problem 1MRE

The value of the given numerical expression is $\boxed{-4}$

Explanation of Solution

Given information: $\left(-5+9\right)+\left(-8\right)$

Concept Involved:

When adding integer with same sign we need find their sum and retain the sign of the larger number to the answer.

When adding integers with different signs we need to find their difference and retain the sign of the larger number to the answer.

When subtracting integers, we need to change the subtraction problem to addition problem by changing the sign of the integer we are subtracting, then following the rules of adding integers.

Calculation: Use the rule of adding integers to add $-5+9$ in the expression $\left(-5+9\right)+\left(-8\right)$

  $4+\left(-8\right)$

Use the rule of addition again to get the final result

  $-4$

Conclusion:

The value of the numerical expression $\left(-5+9\right)+\left(-8\right)$ is $\boxed{-4}$