Answer:
Step-by-step explanation:
Let 
y=2x-10
Switch x and y,
x=2y-10
x+10=2y
(x/2)+5=y
So 
Answer:
Yes! Our total savings on gas proportional to the number of beverages you purchase.
Step-by-step explanation:
Here, each liter of gas costs $3.
Every beverage you purchase you save $0.20.
So, if you purchase for $9, you will save 3*$0.20 = $0.60
So, this is proportional because when increase in purchase, there is proportional increase in savings.
Answer:
12
Step-by-step explanation:
You do what's in parentheses first, but everything is in parentheses so it's pretty much ineffective. In PEMDAS, addition and subtraction are coupled so you do them left to right. 6-1 is 5 and 5+7 is 12.
Subtract the second equation from double the first equation:
2x+6y-2x-(-4y)=0
10y=0
Therefore, y=0. Substituting this into the first equation, we see that:
x+3(0)=3
x=3
Therefore, x=3. The solution to this system is x=3, y=0, or (3, 0).
