our difference is 2 we have a sum of 12 what number are we blank and 7

Question

our difference is 2.we have a sum of 12 what number are we _ and 7

Answer 1

Latesha

 

Start by assuming that x is the number we are looking for.

 

We know that the sum of x and 7 is 12. We can write this as the following equation:

 

x + 7 = 12

 

Now get x only on one side of the equation by subtracting 7 from both sides of the equation. (Note that if we subtract 7 from both sides then the two sides of the equation remain equal.)

 

x + 7 - 7 = 12 - 7

x = 5

 

Check to make sure that the difference between the number and 7 is 2. We see that it is.

 

So the number you are looking for is 5.

Answer 2

Let's remember our addition and subtraction "fact family."  We need two addition facts and two subtraction facts.  We have two of the three numbers needed to complete the family.  So...

 

"Difference" means subtraction and

"Sum" means addition.

 

Let's construct all four of the family facts...

 

? +7 = 12......fact #1, addition

7 + ? = 12.....fact #2, addition

12 - 7 = ?......fact #3, subtraction

12 - ? = 7......fact #4, subtraction

 

From fact #3, we find that...

12 - 7 = ?

       ? = 5

 

We now have all three numbers to complete our fact family, now let's check our work...

5 + 7 = 12

    12 = 12....true, √check, fact #1

7 + 5 = 12

    12 = 12....true, √check, fact #2

12 - 7 = 5

       5 = 5....true, √check, fact #3

12 - 5 = 7

       7 = 7....true, √check, fact #4

 

and...7 - 5 = 2....true, √check, problem wording.

 

Your missing number is equal to 5.  Always check your solutions and work!