I think we need a coordinate grid for that,,
Answer:
Demetrius's account is $84 higher after the two transactions
Step-by-step explanation:
Let
x -----> original amount in Demetrius's account
y ----> amount in Demetrius's account after the deposit and the withdraws
we know that
The amount in Demetrius's account after the two transactions must be equal to the original amount in Demetrius's account plus the deposit minus the withdraws
so


therefore
Demetrius's account is $84 higher after the two transactions

Use the rational root theorem:

=16,

=1
The dividers of

: 1,2,4,8,16
The dividers of

: 1
Therefore, check the following rational numbers: +-


is a root of the expression, so factor out x-4
Compute

to get the rest of the equation.

Cancel the common factor:

is the final answer
Each of 4 friends has 2 balloons
4 x 2 = 8
herself has one
so 8 + 1 = 9
answer: Total 9 balloons