Yoshi is 5% taller today than she was one year ago. Her current height is 168 cm. How tall was she one year ago
2 answers:
You might be interested in
Answer:
y =
Step-by-step explanation:
When doing problems like these, you should go through the process like using PEMDAS:
P - Parenthesis ()
E - Exponents
M - Multiply x
D - Division ÷
A - Addition +
S - Subtraction -
1) Since there aren't any Parentheses, or exponents, we should then check for any use of Multiplication.
As shown, there are no shown methods of multiplying.
BUT there is Division, so we will do the opposite of division, which is multiplication.
K = m - n ÷ y
y(K = m - n ÷ y)y
^ Trying to multiply 'y' onto both sides, because when you do something to one side, you do to the other. ^
'y' then cancels out on one side, so you will be left with:
= m - n
But on the other side you will have:
Ky
So your problem will look like:
Ky = m - n
2) Since we are trying to get 'y' by itself, instead of multiplying now, we will be dividing, because:
K(y) = Ky or you can also say K x y = Ky
Back to the problem, we will now divide 'K' to both sides, as stated before:
What you do to one side, you do to the other:
'K' will cancel out on one side:
Leaving you with:
'y'
While the other side, will be left as:
So your final answer will be:
Answer:
13.2 years
Step-by-step explanation:
The decay rate is 15%, so the decay factor is 1 - 15% = 0.85. Then the exponential equation for the value is ...
v(t) = 85000·0.85^t
We can set v(t) = 10,000 and solve for t:
10000 = 85000·0.85^t
10000/85000 = 0.85^t . . . . divide by 85000
log(2/17) = t·log(0.85) . . . . . .reduce fraction, take logs
t = log(2/17)/log(0.85) ≈ 13.2
It will take about 13.2 years for the value to fall below $10,000.
_____
Such a question is nicely answered by a graphing calculator.
