Final answer:
To simplify the expression 3x + 2y - 4x + 5y + 7x - 9y, combine like terms to get 6x - 2y. Check your answer by ensuring correct arithmetic operations on coefficients.
Step-by-step explanation:
To simplify the expression 3x + 2y - 4x + 5y + 7x - 9y, you need to combine like terms. This means adding or subtracting coefficients of the same variable.
First, combine the x terms:
- 3x - 4x + 7x = (3 - 4 + 7)x = 6x
Next, combine the y terms:
- 2y + 5y - 9y = (2 + 5 - 9)y = -2y
Putting them together gives you:
6x + (-2y) = 6x - 2y
Check to see if the answer is reasonable: Isolate the coefficients of x and y and make sure that the signs and arithmetic operations were applied correctly.