What is the sum of the first 14 terms of the sequence : an=6n-12

Mathematics

1 answer:

Gemiola [76]2 years ago

5 0

A1=6*1-12=-6 arithmetic sequence
a14=6*14-12=72
sum =n(a(1)+a(n))/2
sum =14*(-6+72)/2=462

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ok so if you have 3 and 1/4 pizza and want to subtract 3/4 out of it,and get 3x more slices then you had from a friend after sub

Brilliant_brown [7]

Answer:

You have 2 and 1/2 pizzas and your friend has 5/6 of a pizza.

Step-by-step explanation:

You have 3 1/4 pizzas. If you get rid of 3/4 of a pizza, you will end up with 2 2/4 pizzas.

To make it easier, you can just change the values into improper fractions: 3 1/4 = 13/4

13/4 - 3/4 = 10/4

10/4 = 2 2/4 pizzas

(2 2/4 = 2 1/2)

Anyways! You now have 2 and a half pizzas. You have 3 times the amount of pizza that your friend has. In other words, your friend has 1/3 the amount of pizza that you have. You can solve for this in two ways, whichever way you solve it is up to you.

You can solve this problem by dividing the amount of food you have by 3: $\frac{2\frac{1}{2} }{3}$ which equals 0.8333... (the 3 is repeating). But you can just keep your final answer in fraction form if you want to: $\frac{2.5}{3} = \frac{5}{6}$
You can solve this problem by multiplying 1/3 to the amount of food you have: $\frac{1}{3} * 2 \frac{2}{4}\\=\frac{10}{12}\\ =\frac{5}{6}$