Problem 45

Question

Find each sum without the use of a number line. $$3.5+(-45)+(-8.4)+72$$

Step-by-Step Solution

Verified
Answer
The sum is \(22.1\).
1Step 1: Simplify the Problem
Since this problem simply involves addition, it doesn't matter in which order the numbers are added. However, grouping positive and negative numbers together can help simplify the problem. Thus, separate the positive numbers from the negative numbers. \[3.5+72\] and \[(-45)+(-8.4)\]
2Step 2: Adding Up the Numbers
Now, add the separated positive and negative numbers together. You get \(3.5+72 = 75.5\) for the positive numbers, and for the negative numbers, the sum is \(-45 -8.4 = -53.4\). Remember, adding a negative number is equivalent to subtracting that number. Therefore, \(-45 + (-8.4)\) is the same as \(-45 - 8.4\).
3Step 3: Final Sum
Finally, sum the resulting numbers from step 2 which are 75.5 and -53.4. The operation will be \(75.5 +(-53.4)\) which is the same as \( 75.5 - 53.4 = 22.1\)