Question

(3а-2b)^2-9a(a-2b) даю 20 баллов

Answer 1

(3a - 2b)² - 9a(a - 2b) = 9a² - 12ab + 4b² - 9a² + 18ab = 6ab + 4b²

Answer 2

To simplify the expression (3а-2b)^2 - 9a(a-2b), let's start by expanding the square term (3а-2b)^2 and then simplify the entire expression:

Step 1: Expand the square term (3а-2b)^2: (3а-2b)^2 = (3а-2b)(3а-2b) = 3а * 3а + 3а * (-2b) - 2b * 3а - 2b * (-2b) = 9а^2 - 6ab - 6ab + 4b^2 = 9а^2 - 12ab + 4b^2

Step 2: Simplify the entire expression by substituting the expanded square term: (3а-2b)^2 - 9a(a-2b) = (9а^2 - 12ab + 4b^2) - 9a(a-2b)

Step 3: Distribute the -9a through the parentheses: (9а^2 - 12ab + 4b^2) - 9a(a-2b) = 9а^2 - 12ab + 4b^2 - 9a^2 + 18ab

Step 4: Combine like terms: 9а^2 - 12ab + 4b^2 - 9a^2 + 18ab = (9а^2 - 9a^2) + (-12ab + 18ab) + 4b^2 = 0 + 6ab + 4b^2 = 6ab + 4b^2

The simplified expression is 6ab + 4b^2.