Final answer:
The side length of a square with a perimeter of 12x+4y is found by dividing the perimeter by 4, which results in the side length being 3x + y.
Step-by-step explanation:
The student is asking for the length of the side of a square when the perimeter is given as 12x+4y. To find the side length of a square, we will use the perimeter formula for a square, which is P = 4s, where P is the perimeter and s is the side length of the square.
To find the side length, we divide the total perimeter by 4:
s = (12x + 4y) / 4
Breaking this down we get:
s = (4 × 3x) / 4 + (4 × y) / 4
s = 3x + y
Therefore, the expression that represents the side length of the square is 3x + y.