The area (in square feet) of the school sign can be represented by $15x^2-x-2$ . a. Write an expression that represents the length of the sign. length: ft Question 2 b. Describe two ways to find the area of the sign when $x=3$ . 1. Substitute for into the expression for the area $15x^2-x-2$ , then simplify. 2. Substitute for into the expressions for the length $\text{(}$ $\text{)}$ and width $\left(3x+1\right)$ , simplify each, then multiply these two numbers.