Remark
I take it you want the integers to this problem.
Givens
The smallest integer = x - 1
The middle integer = x
The largest integer = x + 1
Equation
3( x - 1 + x) = 4(x + 1) + 1 Remove the brackets on both sides.
3(2x - 1) = 4x + 4 + 1
6x - 3 = 4x + 5 Subtract 5 from both sides.
-3 - 5 + 6x = 4x
- 8 + 6x = 4x Subtract 6x from both sides
- 8 = 4x - 6x
- 8 = -2x Divide by -2
-8/-2 = x
x = 4
Check
smallest integer = 3
middle integer = 4
largest integer = 5
3(3 + 4) = 4(5) + 1
3(7) = 4(5) + 1
21 = 20 + 1
21 = 21 and it checks.
Answer
the smallest number is 3
the middle number is 4
The largest number = 5