Answer:
x=5/2
Step-by-step explanation:
Calculate, rewrite, remove the paretheses
Collect the like terms
Swap sides 75=30x swap to 30x=75
Then divide both sides
POH is the -log [ OH- ]. Using this equation, simply find the -log of the OH- concentration to find the pOH:
pOH = - log ( 0.000086 ) = 4.07
680 is the answer to that question
The amount in account after 7 years is $ 5499.445
<em><u>Solution:</u></em>
<em><u>The formula for total amount in compound interest is given as:</u></em>

A = the future value of the investment/loan, including interest
P = the principal investment amount (the initial deposit or loan amount)
r = the annual interest rate (decimal)
n = the number of times that interest is compounded per unit t
t = the time the money is invested or borrowed for
Here given that,
A = ?
P = 4000
t = 7 years

n = 2 ( since compounded semi annually)
<em><u>Substituting the values in formula, we get</u></em>

Thus amount in account after 7 years is $ 5499.445