Question

Find the sum or difference. (Lessons 1.5, 1.6)

– 17 + (– 12)

Short answer

The sum is– 29

Step-by-step solution

Apply the concept of adding or subtracting integers 

Rule: The sum of any integer and its opposite is equal to zero.

Rule: Adding two positive integers always gives a positive integer; adding two negative integers always gives a negative integer.

Rule: To find the sum of a positive and a negative integer, take the absolute value of each integer and then subtract these values.

Explanation: How to add or subtract the integers.

To add two numbers with the same sign, first add the two numbers and then put their common sign before the answer.

To add two numbers with the opposite sign, subtract the smaller number from the bigger number. Then put the sign of the bigger number before the answer.

Find the sum – 17 + (– 12) 

To add two integers, we need to check the signs of those two integers.

Rule: If they are with the same sign (positive or negative),first add the two numbers ignoring the sign and then put their common sign (positive or negative) before the answer.

Here both the numbers are negative, we need to add the numbers and put their common sign negative before the answer.

Now Evaluate:– 17 + (– 12)

$-17+(-12)=-(17+12)=-29$

We can write: – 17 + (– 12) = – 29