Answer:
variable, In algebra, a symbol (usually a letter) standing in for an unknown numerical value in an equation. Commonly used variables include x and y (real-number unknowns), z (complex-number unknowns), t (time), r (radius), and s (arc length).
Answer:
x=2
Step-by-step explanation:
Perimeter of a square = 4*(side of the square)
28 = 4*(3x+1)
28 = 12x + 4
28- 4 = 12x
24 = 12x
x =2
85 is the correct answer.