Question

If (A = 3y + 9x - 3xy)
(B = 6x - 2y + 3xy)
(C = 9x - 3xy - y), then find (A + B - C).

• A. 3x + 3xy + 2y
• B. 6x + 3xy - 2y
• C. 6x - 3xy + 2y
• D. 6x + 3xy + 2y

Answer 1

The correct option is D 6x + 3xy + 2y

Given: (A = 3y + 9x - 3xy)
(B = 6x - 2y + 3xy)
(C = 9x - 3xy - y)
(A+B =(3y + 9x - 3xy) + (6x - 2y + 3xy)
Grouping the like terms together,
= (3y - 2y) + (9x + 6x) + (- 3xy + 3xy)
= y + 15x ---(i)

Now subtracting C from (i),
= (y + 15x) - (9x - 3xy - y)
Grouping the like terms together,
= (y + y) + (15x - 9x) + (3xy)
= 2y + 6x + 3xy
Rearranging the terms we get,
(6x + 3xy + 2y).