I'm not sure if it's right, but I think the answer is 648.
Answer:
Step-by-step explanation:
we know that
The simple interest formula is equal to
where
I is the Final Interest Value
P is the Principal amount of money to be invested
r is the rate of interest
t is Number of Time Periods
in this problem we have
Bank A
substitute in the formula above
Bank B
substitute in the formula above
Bank C
substitute in the formula above
Find the average interest gained from the three accounts in one year
Answer:
x=-6 y=7
Step-by-step explanation:
8x+5y=-13; x+y=1
Isolate x and substitute
(-13-5y)/8 +y=1
Isolate y
y=7
substitute y=7
(-13-5*7)/8=-6