Answer:
-34
Step-by-step explanation:
a + b = -6
x + y + z = -2
We want 8a so multiply the first equation by 8
8( a + b) = -6*8
8a+8b = -48
We also want -7x so multiply the second equation by -7
-7(x + y + z) = -2*-7
-7x-7y-7z = 14
Add the two equations together
8a+8b = -48
-7x-7y-7z = 14
-------------------------
8a+8b-7x-7y-7z = -34
Rearranging the order
8a - 7x - 7z - 7y + 8b = -34
Each number in the code can be 1 of 10 numbers.
The total number of possible combinations is 10 * 10 * 10 * 10 = 10,000
The probability of getting 1234 would be 1/10,000
a since 3 is positive and one is negative
You have 1/4 + 1/4 + 1/4 + 3/8 + 3/8 + 5/8 + 5/8 + 5/8 + 5/8 + 1
this can reduce to 3/4 + 6/8 + 20/8 +1
6/8 = 3/4 so you have 3/4 + 3/4 + 20/8 + 1
6/4 + 20/8 + 1
you can change the denominator to 4 to make it easier=
6/4 + 10/4 + 4/4 = 20/4 = 5
5 gallons
