SOLUTION: I don't understand the "moving" part. I'm not sure when to add and when to subtract. And if the numbers are negative or positive. I do understand the distributive part though.

Algebra ->  Equations -> SOLUTION: I don't understand the "moving" part. I'm not sure when to add and when to subtract. And if the numbers are negative or positive. I do understand the distributive part though.      Log On


   

Question 116595This question is from textbook Basic College Math
: I don't understand the "moving" part. I'm not sure when to add and when to subtract. And if the numbers are negative or positive. I do understand the distributive part though. This question is from textbook Basic College Math

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

Means: you need to “add” to find the "sum," and you need to “subtract” to find the "difference"
Positivenumbers are any numbers greater than zero, for example: 1, 2.9, 3.14, 40000
1%3E0
3.14%3E0
Negativenumbers are any numbers less than zero, for example: -1, -2.9, -3.14, -40000
-1%3C0
-3.14%3C0
We do not consider zero to be a positive or negative number.
The sum+of any number and its opposite is 0.
If we have number 3, its opposite is -3; then, their sum is 3+%2B%28-3%29+=+3-3+=+0
The sign+of+a+number refers to whether the number is positive or negative, for example:
the sign of -3 is minus or negative, and the sign of 442 is plus or positive. As you can see, we don’t have to write + sign in front of positive number ( when we see 442, we know it is +442)

Adding Positive and Negative Numbers
When adding numbers of the same sign, we add their absolute+values, and give the result the same+sign.
%28%2B2%29+%2B+%28%2B5%29+=+%28%2B7%29
When adding numbers of the opposite signs, we take their absolute values, subtract the smaller from the larger, and give the result the sign of the number with the larger absolute value.
%28-2%29+%2B+%28%2B5%29+=+%28%2B3%29………. subtract the 2 from the 5( (+5) has larger absolute value) and give the result the sign of the number with the larger absolute value, number (+5)
Or, you can have this;
%28%2B2%29+%2B+%28-5%29+=+%28-3%29……….
Subtracting Positive and Negative Numbers
Subtracting a number is the same as adding its opposite; we convert the subtracted number to its opposite, and add the two numbers.
7+-+4+=+7+%2B+%28-4%29+=+2
the result of subtracting two numbers can be positive, can be negative, or can be 0
Multiplying Positive and Negative Numbers
Simple rules:
+*+ = +………. both numbers are positive, their product will be positive
+*- = -…………if one number is positive and the other one is negative,
-*+ = -………… their product will be negative
-*- = +………. both numbers are negative, their product will be positive
Dividing Positive and Negative Numbers
a. If both numbers are positive, we just divide as usual
b. If both numbers are negative, so we divide the absolute value of the first by the absolute value of the second
%28-4%29%2F%28-2%29+=+4%2F2=2
c. if both number have different signs, so we divide the absolute value of the first number by the absolute value of the second and give this result a negative sign
%28-4%29%2F%282%29+=+-4%2F2=-2