Answer:
8x + 6y
Explanation:
Given the following algebraic expression;
4x - 9y ......equation 1
3x + 4y ......equation 2
9x - 7y ......equation 3
First of all, we would sum up eqn 2 & 3;
(3x + 4y + 9x - 7y)
Collecting like terms, we have;
3x + 9x + 4y - 7y = 12x - 3y .......equation 4
Next, we would subtract eqn 1 from eqn 4;
12x - 3y - (4x - 9y) =
12x - 3y - 4x + 9y =
12x - 4x - 3y + 9y =
8x + 6y
