I don’t understand how to do this

Question

Find the value of 3 consecutive integers such that the sum of the first and the second is 20 less than three times the third.

Answer 1

the key is that 3 consecutive integers can be represented as x, x+1, and x+2.

The sum of the 1st and 2nd is then x + (x+1). That sum is 20 less then 3 times the 3rd.

Well here is 3 times the third: 3(x + 2). and 20 less than that is 3(x+2) - 20.

Now we are ready to write an equation.

x + (x +1) = 3(x+2) - 20 where the equal sign replaces the word "is" in the word problem.

See if you can take if from there to realize that the smallest (first) integer is 15 (represented by x).

Answer 2

x, x + 1, x + 2 are 3 consequtive integers. Then x + (x + 1) = 3(x + 2) - 20; 2x + 1 = 3x - 14; x = 15

So given 3 numbers: 15, 16, 17