Question

17 3x + 7 - 7y + 2x - 3y - 1 5x - 10y + 6
18 -9x - y + 1 + 5y + 5x - 10 -4x + 4y - 9
19 -x + 8 + 6x - 4y - 8x + 3 -3x - 4y + 11
20 4x - 7 + y - 7x - (-3y) -3x + 4y - 7
21 8x - 5y - x + 9 - y 7x - 6y + 9

Explanation:

Let's solve problem 21: \(8x - 5y - x + 9 - y\)

Step1: Combine like terms for \(x\)

\(8x - x = 7x\)

Step2: Combine like terms for \(y\)

\(-5y - y = -6y\)

Step3: The constant term remains \(9\)

So the simplified expression is \(7x - 6y + 9\)

Answer:

\(7x - 6y + 9\)