Combine like terms: 18a - 8b -1
Answer:

Step-by-step explanation:
Let:

We need to eliminate one of the variables, so let's use elimination method. First multiply (1) by 2

Now subtract (2) from 2*(1) in order to eliminate x:

Solving for y:
Multiplying both sides by -1

Finally, replacing the value of y in (1)

Solving for x:
add 41 to both sides:

Multiply both sides by 1/2:

1: <span>Commutative Property
2: </span><span>Distributive Property
3: </span><span>Associative Property
I think that that is the right order. :D</span>