Please help and quickly please and 20 points with brainelest

Thank you

Use addition and subtraction to simplify the following polynomials. a. add polynomials: (3 – 4x + 8x^2) + (–6 + 2x – 5x^2) step 1: rewrite the polynomials without the parentheses. step 2: write the polynomial in descending order and use parentheses around like terms. step 3: add the like terms identified in step 2 to simplify the polynomial. b. subtract polynomials: (3x – 5 – 7x^2) – (–2 + 6x^2 – 5x) step 1: rewrite the polynomials without the parentheses. remember to multiply each term in the second parentheses by –1. show your work. step 2: write the polynomial in descending order and use parentheses around like terms. step 3: add the like terms identified in step 2 to simplify the polynomial.

Tom drove 206 miles in 3.9 hours. estimate his average speed.

Solve for x -3+3b> 9a: ) x> 4b-9/3b: ) x< 9-4b/3c: ) x< -4b+9/-3d: ) x> 4b+9/-3