It takes Melvin 3/10 of an hour to run 3/4 of a five kilometer race if Melvin runs the same pace how long in hours would it take him to run 10 km

Plz 20 points polynomials 1: subtract and simplify (–y^2 – 4y – 8) – (–4y^2 – 6y + 3) 2: multiply and simplify 2x^2 y^3 z^2 · 4xy^4 x^2 3: multiply and simplify (x – 4) (x2 – 5x – 6)