write down three consective numbers of which k is the middle number. The sum of the first and second number is 9 more than the third number. write down a equation to represent this information

Answer 1

If k is used to represent the middle number, then we can write the following expression

for the number before k: k - 1

The number after k could be represented by: k + 1

The sum of the first two numbers could be written as: ( k -1 + k )

We can subtract 9 from this sum and it would be equivalent to the last number: (k - 1 + k) - 9 = k + 1

So the equation would be (k - 1 + k) - 9 = k + 1

We can solve this equation by combining like terms and using inverse operations:

(k - 1 + k) - 9 = k + 1

2k - 1 - 9 = k + 1

2k - 10 = k + 1

2k -10 - k = k + 1 - k

k - 10 = 1

k - 10 + 10 = 1 + 10

k = 11

The middle number is 11. The number before it will be 10 and the number after it will be 12.

NOTE: 10 + 11 - 9 = 12 -