Pls help I’ll give brainliest and Heart and five star. The area (in square feet) of the school sigh can be represented by 15x^2-x-2

a. Write an expression that represents the length of the sign. _

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 expression for the length (__) and width (3x+1) , simplify each, then multiply these two numbers.