1)- 7a² + 2вc - 8c² + 4c² + 2a² - 9 = 2) 2a³ + a² - 17 - 3²+ a⁴+ a² - 20 = 3) 2aв² + 3a²в - 7aв² + 4aв =

Let's simplify each expression step by step. 1) Simplifying \( -7a^2 + 2bc - 8c^2 + 4c^2 + 2a^2 - 9 \): Combine like terms: - \( -7a^2 + 2a^2 = -5a^2 \) - \( -8c^2 + 4c^2 = -4c^2 \) So the expression becomes: \[ -5a^2 + 2bc - 4c^2 - 9 \] 2) Simplifying \( 2a^3 + a^2 - 17 - 3^2 + a^4 + a^2 - 20 \): First, compute \( 3^2 = 9 \). Then, combine like terms: - \( a^4 + 2a^2 + 2a^3 - 17 - 9 - 20 = a^4 + 2a^3 + 2a^2 - 46 \) So the expression becomes: \[ a^4 + 2a^3 + 2a^2 - 46 \] 3) Simplifying \( 2ab^2 + 3a^2b - 7ab^2 + 4ab \): Combine like terms: - \( 2ab^2 - 7ab^2 = -5ab^2 \) So the expression becomes: \[ -5ab^2 + 3a^2b + 4ab \] This can be combined as: \[ 3a^2b - 5ab^2 + 4ab \] Thus, the simplified expressions for each problem are: 1) \( -5a^2 + 2bc - 4c^2 - 9 \) 2) \( a^4 + 2a^3 + 2a^2 - 46 \) 3) \( 3a^2b - 5ab^2 + 4ab \)