The greatest common factor is 3abc
-15x - 3y = 3
-15x - 3(5x-1) = 3 [input y]
-15x - 15x - 3 = 3 [distribute 3 over 5x and -1]
-30x - 3 = 3 [combine like terms]
-30x = 6 [add 3 to eliminate the negative]
x =

[divide by -30 to get x alone]
x =

[reduce the fraction]
Hopefully this is helpful enough to get you to your answer
The answer is letter choice B
(13/20)=(x/152)
1976=20x
x=98.8
About 99 have dogs
We can first convert 9.5 into fraction :
9.5= 9 1/2
Then we can use deduction to find out the answer:
9 1/2 - 6 1/3
=19/2 - 19/3
We change it to the same denominator:
=19×3/6 - 19×2/6
= 57/6 - 38/6
= 19/6
Therefore there are 19/6 or 3 1/6 gallons left in the tank.
Hope it helps!