Question

4SolaDoang.TentangPerkalianPdAljabar! YangSukaBantu,TolongBantuinYaa^^ Pake caranya.

1)(2x + 5) (x2- 2x + 1)

2) (2x2 - 3x + 7) (x + 1)

3) (x + 2) (x - 1) + (3x + 9)

4) x2 + 6x - 5 + (x - 3) (x + 5)

~MakasihYangMauBantu! Pake cara ya? :)

Answer 1

1. (2x + 5) (x² - 2x + 1)
= 2x³ - 4x² + 2x + 5x² - 10x + 5
= 2x³ + x² - 8x + 5

2. (2x² - 3x + 7) (x + 1)
= 2x³ + 2x² - 3x² - 3x + 7x + 7
= 2x³ - x² + 4x + 7

3. (x + 2) (x - 1) + (3x + 9)
= x² - x + 2x - 2 + 3x + 9
= x² + 4x + 7

4. x² + 6x - 5 + (x - 3) (x + 5)
= x² + 6x - 5 + x² + 5x - 3x - 15
= 2x² + 8x - 20

Answer 2

1. (2x + 5) (x² - 2x + 1)
= (2x × x²) (2x × - 2x) (2x × 1)  (5 × x²) (5 × -2x ) (5 × 1)
= 2x³ - 4x² + 2x + 5x² - 10x + 5
= 2x³ - 4x² + 5x² + 2x - 10x + 5
= 2x³ + x² - 8x + 5

2. (2x² - 3x + 7) (x + 1)
= (2x² × x) (2x² × 1)  (-3x × x) (-3x× 1)  (7 × x) (7 × 1)
= 2x³ + 2x² - 3x² - 3x + 7x + 7
= 2x³ - x² - 4x + 7

3. (x + 2) (x - 1) + (3x + 9)
= (x × x) (x × -1)  (2 × x) (2 × -1) + 3x + 9
= x² - x + 2x - 2 + 3x + 9
= x² - x + 2x + 3x - 2 + 9
= x² + 4x + 7

4. x² + 6x - 5 + (x - 3) (x + 5)
= x² + 6x - 5 + (x × x) (x × 5)  (-3 × x) (-3 × 5)
= x² + 6x - 5 + x² + 5x - 3x - 15
= x² + x² + 6x + 5x - 3x - 5 - 15
= 2x² + 8x - 20