$a_1=0.5\\a_2=-0.1\\a_3=0.02\\a_4=-0.004\\a_5=0.0008\\\\a_n=a_1\cdot q^{n-1}\\\\q=a_2:a_1\to q=-0.1:0.5=-0.2\\\\a_n=0.5\cdot(-0.2)^{n-1}=0.5\cdot(-0,2)^n\cdot(-0.2)^{-1}\\\\=0.5\cdot(-0.2)^n\cdot(-5)=-2.5\cdot(-0.2)^n\\\\\boxed{a_n=-2.5\cdot(-0.2)^n}$

6 0

3 years ago

A small tree is 80 cm tall.

ruslelena [56]

1.2 meters = 120 centimeters
amount of increase = 120-80 = 40 centimeters
40 ÷ 80 = 0.5 = 50%
There was a 50% increase.

7 0

3 years ago

In Europe, gasoline efficiency is measured in km/L. If your car's gas mileage is 31.0mi/gal , how many liters of gasoline would

maw [93]

We need to convert the mileage from mi/gal units into to km/L units using the conversion factors.

(31.0 mi/gal) x (1 km / 0.6214 mi) x (1 gal / 3.78 L) = 13.20 km/L

Next, we divide the distance by the mileage.
(142 km) / (13.20 km/L) = 10.79 L

<span>Therefore, you need 10.79 liters of gasoline.</span>

7 0

3 years ago

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