Ed borrowed 1,500 for 4 months at 13.5 %. How much did he have to pay back under an add-on plan?
To calculate how much Ed had to pay back under an add-on plan, we need to add the interest to the principal amount.
First, let's calculate the interest:
Interest = Principal * Rate * Time
Principal = $1,500
Rate = 13.5% (convert to decimal by dividing by 100: 13.5/100 = 0.135)
Time = 4 months
Interest = $1,500 * 0.135 * 4 = $810
Now, let's add the interest to the principal:
Total amount to pay back = Principal + Interest = $1,500 + $810 = $2,310
Therefore, Ed had to pay back $2,310 under the add-on plan.
^ and log are inverse operations
x+8 - 8 = x
x/8 * 8 = x
(√x)^2 = x
log88x = x
8log8x = x
The thing that makes logs initially so confusing is the notation. If we had a cute symbol like + or / or √ things would be a lot easier.
The definition of log8x is that power of 8 which we need to get x.
Now, 9^x = 57 is a bit trickier. Recall that
log9N is the power of 9 you need to get N. So,
log957 is the power of 9 you need to get 57.
Taking log9 of both sides gives you
log99x = log957
But since log99x = x, you end up with
x = log957