write an equation

Question

The sum of two numbers is three times the smaller. the sum of the two numbers is 6.what are the nunbers? 

Answer 1

Let x and y be the two unknown numbers.  The sum of the two numbers is 6:

 

x + y = 6  (so y = 6 - x)

 

The sum of two numbers is three times the smaller:

 

x + y = 3y

 

Since y = 6-x, substitute 6-x for y:

 

x + y = 3y

x + 6 - x = 3(6-x)

6 = 18 - 3x

3x = 12

x = 4

 

y = 6 - x

y = 6 - 4

y = 2

 

Check:

x + y = 6

4 + 2 = 6

6 = 6

Check!

 

x + y = 3y

4 + 2 = 3*2

6 = 6

Check!