one number is 3 less than twice the other if their sum is 39 find the numbers

Question

be as detailed as possible. Thank you (:

Answer 1

Let the numbers be x and y

 

One number is 3 less than twice the other so:

x = 2y-3

 

Their sum is 39 so

x+y = 39

 

We have two equations:

x = 2y-3     equation1

x+y=39      equation2

 

We can use the value of 2y-3 from equation1 and

substitute that in place of x in equation 2:

 

(2y-3)+y = 39     clear the parenthesis

2y-3+y=39         combine the y terms

3y-3=39             add 3 to both sides

3y-3+3 = 39+3

3y = 42              divide both sides by 3

3y/3 = 42/3

y = 14

 

Since x + y = 39 and y = 14:

x+14=39

x + 14-14=39-14

x = 25

 

Your numbers are 14, and 25

 

Check:

 

 2x-3=25                     x+y=39

 2(14)-3=25                14+25=39

 25 = 25                      39 = 39

              

Our answer fits the conditions given in the problem.

 

 

Answer 2

1. 2y - x = 3
2. x + y = 39

 

From equation 2, x = 39-y

Substituting for x into equation 1, we get

 

2y -(39-y) = 3

2y -39 + y = 3

 

Collecting like terms,

 

2y + y = 3+39

3y = 42

y = 14

 

x = 39 - y = 39 - 14 = 25

 

• x = 25
• y = 14
• the two numbers are 12 and 27