Question 652552
let x = first, smaller, integer
let x + 1 = next, larger, consecutive integer (this is always true)

"sum of two consecutive integers":
x + (x + 1) or
2x + 1 simplified.

"if 9 is subtracted from it..."

2x + 1 - 9 or
2x - 8 simplified.

"The result is(=) 3 more than the larger of the integers"
=  (x + 1) + 3

so,
2x - 8 = (x + 1) + 3
2x - 8 = x + 4 
x - 8 = 4 (subtracted x from both sides)
x = 12 (added 8 to both sides)

If x = 12, then the next number is 13.

12, 13