Answer:
y = 0
Step-by-step explanation:
It is always a good idea to look at the question and make some observations about it. Here, you might observe ...
- all of the bases are powers of 3: 243 = 3^5; 9 = 3^2
- y is a factor of every exponent
The latter observation is important, because it means that when y=0, every exponential expression has a value of 1. Hence y = 0 is a solution.
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To solve the equation, you can write it in terms of powers of 3.
(3^5)^(-y) = (3^-5)^(3y)·(3^2)^(-2y)
3^(-5y) = 3^(-15y)·3^(-4y)
3^(-5y) = 3^(-19y)
-5y = -19y . . . . . . . . equating exponents; equivalent to taking log base 3
14y = 0 . . . . . . . . . . add 19y
y = 0 . . . . . . . . . . . one solution
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The rules of exponents we used are ...
(a^b)(a^c) = a^(b+c)
(a^b)^c = a^(bc)
1/a^b = a^-b
Add the pic and I’ll be able to answer it
Answer:
$3.88
Step-by-step explanation:
You want to leave a 18% tip on a meal that cost $21.58.
First, convert the 18% to an actual number that can be used in a calculation. For percents,this is always done by simply dividing the percent (in this case 18%) by 100%.So, the conversational term "18%" becomes 18% / 100% = 0.18 in terms of a real mathematical number.
Second, you need to find out what 18% of your $21.58 meal cost is.This is always done by multiplying 0.18 by $21.58, or 0.18 x $21.58=$3.88.
So, the amount of tip you are going to leave is $3.88.
Add all numbers and divide the total by how many numbers there are