Penjelasan dengan langkah-langkah:

1. 3(2x-x) = (3 × 2x) + (3 × (-x))

= 6x + (-3x)

= 6x - 3x

= 3x

2. 5(x+y+2) = (5 × x) + (5 × y) + (5 × 2)

= 5x + 5y + 10

3. -4(a+4b) = ( -4 × a) + (-4 × 4b)

= -4a + (-16b)

= -4a - 16b

4. (-x+5y)+(5x+y) = (-x × 5x) + (-x × y) + (5y × 5y) + (5y × y)

= -5x² + (-xy) + 25y² + 5y²

= -5x² - xy + (25y² + 5y²)

= -5x2 - xy + 30y²

5. (7a+4b)+(-6a-8b) = (7a × (-6a)) + (7a × (-8b)) + (4b × (-6a))

+ (4b × (-8b))

= -42a² + (-56ab) + (-24ab) + (-32b²)

= -42a² - 56ab - 24ab - 32b²

= -42a² - 80ab - 32b²