The common ratio is -5, note that each value is the previous value multiplied by -5.
Multiply the first equation by -2 gives:_
-2y = -8 + 2x
2y = 8 - 2x
adding these 2 equations:-
0 = 0
This shows that the 2 equations are equal so there are infinite solutions
Answer:
Step-by-step explanation:
We know that since angles in a triangle add up to 180º, the remaining angle must be 45º.
So the side with length 
must be equal to the side with length 
. That is:
Now, by Pythagoras:
The answer is 28 years
At = A0 * e^(-k * t)
At = 12 g
A0 = 15 g
k = 7.9 × 10^-3 = 0.0079
t = ?
12 = 15 * e^(-0.0079 * t)
12/15 = e^(-0.0079 * t)
0.8 = e^(-0.0079 * t)
Logarithm both sides (because ln(e) = 1:
ln(0.8) = ln(e^(-0.0079 * t))
ln(0.8) = (-0.0079 * t) * ln(e)
-0.223 = -0.0079 * t
t = -0.223 / -0.0079
t = 28.23
t ≈ 28 years
60 minutes=1 hour
360 minutes=6 hours
so 360 minutes/90 minutes
so your answer is 4 hours
