Multiply (3x2 – 4xy + 2y2 ) by (2x – y) and find the value of the product, when x = -1 and y =2.
Answers
Answer:
6x³ - 11x²y + 8xy² - 2y³ = -76
Step-by-step explanation:
(3x² – 4xy + 2y²) x (2x – y)
= 2x(3x² – 4xy + 2y²) - y(3x² – 4xy + 2y²)
= 2x(3x²) - 2x(4xy) + 2x(2y²) - {y(3x²) - y(4xy) + y(2y²)}
= 6x³ - 8x²y + 4xy² - {3x²y - 4xy² + 2y³}
= 6x³ - 8x²y + 4xy² - 3x²y + 4xy² - 2y³
= 6x³ - 8x²y - 3x²y + 4xy² + 4xy² - 2y³
= 6x³ - 11x²y + 8xy² - 2y³
When x = -1 and y = 2,
6x³ - 11x²y + 8xy² - 2y³
= 6(-1)³ - 11(-1)²(2) + 8(-1)(2)² - 2(2)³
= 6(-1) - 11(1)(2) + 8(-1)(4) - 2(8)
= -6 - 22 - 32 - 16
= -76
Answer:
6x³ - 11x²y + 8xy² - 2y³ = -76
Step -by-step explanation:
(3x² – 4xy + 2y²) x (2x – y)
= 2x(3x² – 4xy + 2y²) - y(3x² – 4xy + 2y²)
= 2x(3x²) - 2x(4xy) + 2x(2y²) - {y(3x²) - y(4xy) + y(2y²)}
= 6x³ - 8x²y + 4xy² - {3x²y - 4xy² + 2y³}
= 6x³ - 8x²y + 4xy² - 3x²y + 4xy² - 2y³
= 6x³ - 8x²y - 3x²y + 4xy² + 4xy² - 2y³
= 6x³ - 11x²y + 8xy² - 2y³
When x = -1 and y = 2,
6x³ - 11x²y + 8xy² - 2y³
= 6(-1)³ - 11(-1)²(2) + 8(-1)(2)² - 2(2)³
= 6(-1) - 11(1)(2) + 8(-1)(4) - 2(8)
= -6 - 22 - 32 - 16
= -76