If you're describing a time, then it has to have a unit of time. We have no idea how much gas you're talking about, so second, minute, and hour are all possibilities.
y+z=10
x+z=8
x+y=12
(y+z)-(x+z)=10-8
y-x=2
y-x=2
y+x=12
solve simultaneously
x=5, y=7
then substitute to get z=3
hence xyz=573
Answer:
b = 
Step-by-step explanation:
b +
= 1
← change to an improper fraction
b +
= 
Multiply through by 12 ( the LCM of 3 and 4 ) to clear the fractions
12b + 8 = 15 ( subtract 8 from both sides )
12b = 7 ( divide both sides by 12 )
b = 
Answer:
infinite solutions
Step-by-step explanation:
replace x with 3y + 9 in the second equation
9 - (3y + 9) = -3y ➡ 9 -3y -9 = -3y ➡9-9 = 3y-3y ➡ 0 = 0
this means whatever numver you write instead of y there will be a solution.