I think it is"A" hope it help
Answer:
-12.75
Step-by-step explanation:
Find the product of 51 and -2.5. Use the distributive property to rewrite and solve.
The next step using Distributive property is to expand the brackets
5.1 × 2.5
Step 1: Distributive property
51(-2.0) + 51(-0.5)
Step 2: Expand the brackets
-10.2 + -2.55
Step 3
- 12.75
a. The first variable is x and the second variable is y.
b. The equations are
and 
Step-by-step explanation:
Step 1:
The first step is to define the variables. The variables can be any two symbols, letters, characters, etc.
Here let the first variable be x and the let the second variable be y.
So the variables are defined as x and y.
Step 2:
The sum of the given variables is 12.
The first variable + the second variable = 12,

The difference between the two variables is 4.
The first variable - the second variable = 4.

Step 3:
If we add both the equations we get,
and 
x = 8 and y = 4.
Answer:
The correct answer is OB.
Step-by-step explanation:
Let us recall the Associative Property of Addition: given three real numbers
,
and
the following equality holds:
.
Let us remark that the Associative Property of Addition tells us that we can perform the sums in any order. So,
.
In the other options there was used the Commutative Property of Addition.