Question

Срочно даю 10 баллов
(3x + 2y)^2 - 3x(2x + 3y) при x = 3, y = 1

Answer 1

Ответ:

40

Объяснение:

${(3x + 2y)}^{2} - 3x(2x + 3y) = (9 {x}^{2} + 2 \times 3x \times 2y + 4 {y}^{2} ) - 3x \times 2x - 3x \times 3y = 9 {x}^{2} + 12xy + 4 {y}^{2} - 6 {x}^{2} - 9xy = 3 {x}^{2} + 3xy + 4 {y}^{2} = 3 \times 3 {}^{2} + 3 \times 3 \times 1 + 4 \times 1 {}^{2} = 27 + 9 + 4 = 40$