Step-by-step explanation:
x is the number
x = 3y + 2
the square
x² = (3y + 2)² = 9y² + 12y + 4
9y² is a multiple of 3 (because of the factor 9)
12y is a multiple of 3 (because of the factor 12)
4 is 1 more than a multiple of 3 (1×3).
so, the sum of all 3 terms is 1 more than a multiple of 3.
