Answer:
$300
Step-by-step explanation:
Here we are given:
Balance at the beginning of last cycle(first half) = $400
Balance halfway through the cycle(second half cycle) = $200
To find the amount Aaron's checking account pay interest last cycle, let's find the average balance.
Use the formula for average:

Average = $300
Therefore, the amount Aaron's checking account pay interest last cycle is $300
Answer:
0.8
Step-by-step explanation:
0.12 ÷ 0.15
= 0.8
There are two ways to do this but the way I prefer is to make one of the equations in terms of one variable and then 'plug this in' to the second equation. I will demonstrate
Look at equation 1,

this can quite easily be manipulated to show

.
Then because there is a y in the second equation (and both equations are simultaneous) we can 'plug in' our new equation where y is in the second one

which can then be solved for x since there is only one variable

and then with our x solution we can work out our y solution by using the equation we manipulated

.
So the solution to these equations is x=-2 when y=6
Answer:
A
Step-by-step explanation:
a+b+c=68
b-3=a
c-5=b
now just solve the system of equations, substitue so that there are only b's in the equation:
a+b+c=68
(b-3) + b + (b+5) = 68
3b=66
b=22
Therefore Barbara is 22