[adding polynomials][section 35]

(1.) (5b + 4c + 8d) + (8b - 7c - 6d) + (3b - 4c)

[here is the problem]

= 16b - 7c + 2d combine like terms

result: 16b - 7c + 2d

(2.) (7x - 2y + 5z) + (8y - 9z) + (7x - 5y)

[here is the problem]

= 14x + y - 4z combine like terms

result: 14x + y - 4z

(3.) (5x + 7y - 10) + (8y - 2x + 3) + (2x - 10y + 4)

[here is the problem]

= 5x + 5y - 3 combine like terms

result: 5x + 5y - 3

(4.) (4a² - 5ab - 6b²) + (10ab - 6a² - 8b²) + (10b² - 3a² - 7ab)

[here is the problem]

= -5a² - 2ab - 4b² combine like terms

result: -5a² - 2ab - 4b²

(5.) (a - b + c) + (b - c - a) + (c - a + b) + (a - 2b - c)

[here is the problem]

= -b combine like terms

result: -b

(6.) (4ab - 5bc + 6ac) - (6bc - 7ab - 8ac) - (10ab - bc - ac)

[here is the problem]

= 4ab - 5bc + 6ac - 6bc + 7ab + 8ac - 10ab + bc + ac

[multiply thru parentheses]

= ab - 10bc + 15ac combine like terms

result: ab - 10bc + 15ac

(7.) (x² + y² - z²) - (3z² - 2x² - 4y²) - (4y² + x² + z²)

[here is the problem]

= x² + y² - z² - 3z² + 2x² + 4y² - 4y² - x² - z²

[multiply thru parentheses]

= 2x² + y² - 5z² combine like terms

result: 2x² + y² - 5z²

(8.) (x² - 6x + 7) - (8x - 15 - x²) - (4x² + 6x - 9) - (7x + 10)

[here is the problem]

= x² - 6x + 7 - 8x + 15 + x² - 4x² - 6x + 9 - 7x - 10

[multiply thru parentheses]

= -2x² - 27x + 21 combine like terms

result: -2x² - 27x + 21

(9.)

(a² - 2ab + b²) - (2ab + a² + b²) - (4a² - 4ab - b²) - (a² - b²)

[here is the problem]

= a² - 2ab + b² - 2ab - a² - b² - 4a² + 4ab + b² - a² + b²

[multiply thru parentheses]

= -5a² + b² combine like terms

result: -5a² + b²

(10.) (a + 2b) - (3b - 4c) - (5a - 7c) - (3b + 2d)

[here is the problem]

= a + 2b - 3b + 4c - 5a + 7c - 3b - 2d multiply thru

= -4a - 4b + 11c - 2d combine like terms

result: -4a - 4b + 11c - 2d