The correct answer is the first option.
If you want to use elimination, you can sum the two equations for example, so that the x's simplify:



Plug this value for y in one of the equations to derive the value of x:

So, the solution is 
Step-by-step explanation:








Answer:
80
Step-by-step explanation:
Since you need 10 loads you know that for 4 loads you use 32 gallons. And to go from 4 to 10 you divide 10 and 4 to get an answer of 2.5. So all you have to do is multiple 32 gallons by 2.5 to then get an answer of 80.
Answer:
Stohr sequence
Step-by-step explanation:
Let a_1=1 and define a_(n+1) to be the least integer greater than a_n which cannot be written as the sum of at most h>=2 addends among the terms a_1, a_2, ..., a_n. This defines the h-Stöhr sequence