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1.(2x+y) (4x-9)
2.(3x+5y2
3.(x-2) (x2-x+3)

1 Answer

4 votes

Answer:

x³ - 3x² + 5x - 6

Explanation:

Multiplication of algebraic expression:

1) (2x + y)(4x - 9) = 2x*(4x - 9) + y(4x - 9)

= 2x*4x - 2x*9 + y*4x - y *9

= 8x² - 18x + 4xy - 9y

2) (3x + 5y)²

Identity : (a + b)² = a² + 2ab + b²

a = 3x and b = 5y

(3x +5y)² = (3x)² + 2 * 3x *5y + (5y)²

= 9x² + 30xy + 25y²

3) (x -2)(x² - x + 3) = x*(x² - x + 3) - 2(x² - x + 3)

=x*x² - x*x + x*3 -2*x² + 2*x - 2*3

= x³ - x² + 3x - 2x² + 2x - 6

=x³ - x² - 2x² + 3x + 2x - 6

Combine like terms. Like terms have same variable with same exponent.

= x³ - 3x² + 5x - 6

User Sanny Srivastava
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