(i) -5xy from 12xy

After subtracting,we get

= 12xy - (- 5xy)

= 5xy + 12xy

= 17xy

(ii) 2a² from -7a²

After subtracting, we get

= 2a² + (-7a²)

= -2a² + 7a²

= -9a²

(iii) 2a-b from 3a-5b

After subtracting, we get

= -(2a – b)+ (3a – 5b)

= -2a + b+ 3a – 5b

= a – 4b

(iv)

After subtracting, we get

= - (2x³ – 4x² + 3x + 5) + (4x³ + x² + x + 6)

= - 2x³ + 4x² – 3x – 5 + 4x³ + x² + x + 6

= 2x³ + 5x² – 2x + 1

(v)

After subtracting, we get

= y² + y² + y – 2 - y³ + y² + 5

= y³ + y² + y + 3

= y³ + y² + y + 3

(vi)

After subtracting, we get

= x + y - z – (x - y - z)

= x - x + y + y - z + z

= + +

= + +

(vii) x² - xy² + xy from x²y + xy² - xy

= x²y + xy² - xy – (x² - xy² + xy)

= x²y – x²y + xy² + xy² - xy - xy

= x²y + xy² - xy

(viii)

After subtracting, we get

= bc - ac – ( - bc + ac)

= bc + bc - ac - ac -

= + -

= + -

= - -

= – 2ac -