Answer:
You got your negatives messed up. The answer was -5y-4x
Explanation:
Expression: -8y + 5x + 3y -9x
Your objective: Simplify the expression
The First step, Combine like terms meaning -8y+3y and -9x+5x
Solve, -8y+3y
That would equal -5y
Next solve -9x + 5x
That would equal -4x
Write your expression in simplest form:
-5y-4x
What you did:
You combined like terms but didn't follow the negative rules
Remember: Positive and Negative = Negative
Negative and Negative = Positive
For example -8y + 3y
You chose to add -8 and 3 which you got -11
What you were supposed to do was to subtract.
A helpful trick: Since they are like terms you could rearrange the questions like this 3y-8y+5x-9x, You can see that you have to do subtraction left to right
3y-8y= -5y
5x-9x= -4x
Solution: -5x-4x