Question 45029This question is from textbook Beginning Algebra
: I am not very good with Algebra. My question is:
Add. -3 + (-4) + (+12)
I do not remember how to do this problem.
I have tried adding it on paper. I have tried adding it up on the calculator. If I remember correctly, 2 negatives = a positive number.
Here is my solution:
-3 + (-4)= 7 + (+12)= 19. Is that correct?
ISBN #0-13-148287-4 Textbook Name is: Beginning Algebra 6th Edition by John Tobey and Jeffrey Slater.
The question is from the Diagnostic Pretest: Beginning Algebra Under Chapter 1 Problem # 7
This question is from textbook Beginning Algebra
Answer by tutorcecilia(2152)   (Show Source):
You can put this solution on YOUR website! Here is a basic review of adding and subtraction numbers:
1). The absolute value of a number is the distance away from zero on the number line. For example the absolute value of 2 is 2 and the absolute value of -2 is also 2. Both are two spaces away from zero on the number line so their absolute value is 2.
.
2). To add two numbers with the same sign, add the absolute values of both numbers and take the common sign:
Example: -3 + -3 = absolute value of -3 + absolute value of -3 = 6. The signs are the same so -3 + -3 = -6
.
3). To add two numbers with different signs, subtract the absolute values and take the sign of the larger number.
Example: -5 + 2 = absolute value of -5 minus absolute value 2 = 3. The signs are different, 5 is the largest and has a negative sign, so = -5 + (+2)= -3
.
4). To subtract any two numbers, change the subtraction sign to addition. Change the sign of the second number to the opposite sign. Apply the rules of addition.
Example: 5-2 = 5 – (+2) Expanded version of the same problem.
5+(-2) Change to an addition problem. Change the sign of the second number.
5+ (-2) = 3 Apply the addition rules for when the signs are different.
.
.
-3 + (-4) + (+12) Since the only operations are addition and subtraction work from left to right.
-3 +(-4)Signs are the same, so add.
-7+(+12) = 5 Signs are different, so subtract and take the sign of the larger number
|
|
|
