In general, the probability of a disjunction is

In this case, A and B are mutually exclusive, so 
This simplifies the formula to

It will be. -3(n+8) because you have to go from greatest to least and then 2 negatives will equal a positive
Answer:
x=3 and y=1
Step-by-step explanation:
subtract equation 2 from 1
then (2x+3y) -(2x+y) =9-7
2x-2x+3y-y =2
2y=2 therefore y=1
substitute y value in 2x+y=7
2x+1=7
2x=7-1
2x=6
x=3