C , I took a guess so if it’s wrong sorry
Answer:
x=30
Step-by-step explanation:
You have to isolate for x. This means you need to somehow get x on one side of the equation all alone. In this case it is x-9=21 which means some unknown number x with 9 subtracted from it is equal to 21. When we bring the -9 over to the other side to get the x all alone, we have to switch the sign of the -9 so it becomes +9. This means x=21+9, and if you add that you'll get 30!
Answer:
13y+15
Explanation:
4y-2.5+ 4y-2.5+ 2.5y+10+ 2.5y+10=13y+15
Price =x
x=30
half of 30 is 15
add 15 to 30
get 45 do that but change you're numbers
The only solution is when y=y
x+1=x-1 subtract x from both sides
1=-1
This is never true so there are no solutions. In this case it is due to the fact that both lines have the same slope and different y-intercepts. This means that they are parallel lines that have a constant distance between them.