Question

Find three consecutive odd integers where the sum of the two largest is seven less than three times the smallest.

Answer 1

Answer:

             13, 15, 17

Step-by-step explanation:

x    - an integer  then  2x + 1 is an odd number  (the smallest one)

consecutive odd numbers increase by 2

so the next odd number (the middle number) is:

2x + 1 + 2 = 2x + 3

and the third (the largest) consecutive is:

2x + 3 + 2 = 2x + 5

the sum of the the two largest numbers is:

2x + 3 + 2x + 5

3 times the smallest number is:  

3(2x + 1)  

the sum of the two largest is seven less than three times the smallest, so:

2x + 3 + 2x + 5 = 3(2x + 1) - 7

4x + 8 = 6x + 3 - 7

   -6x       -6x

-2x + 8 = -4

   -8       -8

-2x  = -12

÷(-2)    ÷(-2)

  x = 6

2x+1 = 2•6+1 = 13

2x+3 = 2•6+3 = 15

2x+5 = 2•6+5 = 17

Check:

2x+3+2x+5 = 15+3+15+5 = 38

38+7 = 45

45÷3 = 15