Answer:
1) 18+2y+4+10+2x+10
2) 42+2y+2x
3) 42+2x=-2y
4) -1(42-2x=2y)
5) (42-2x=2y)/2
y=21-x
Step-by-step explanation:
1) Original equation
2) Combine like terms
3) Since the problem is asking to find the value of Y, Isolate it
4) Multiply by a negative to make Y positive
5) Since what we have left isn't in simplest form, divide by 2
What is left is y=21-x or y=-x+21