It would be called a mess up on ur paper
2=4(-3) + b
2= -12 + b
14= b
Y=4x + 14
Let the number of gallons consumed be the first car be x, and that of the second car, y. Then:
x + y = 50 . . . . . . . (1)
20x + 15y = 850. . . (2)
(1) x 20 => 20x + 20y = 1000 . . . (3)
(2) - (3) => -5y = -150 => y = -150/-5 = 30
From (1), x + 30 = 50 => x = 50 - 30 = 20
Therefore, first car consumed 20 gallons and the second consumed 30 gallons.
To know if it's even based on it's prime factorization, check to see if it is a multiple of 2. If it is, it is an even number. If it is not, it is an odd number.
3^-4 = 1/3^4 = 1/81
hope it helps!