Compute each sum below. If applicable, write your answer as a fraction.
5+5(-2)+5+(-2)^2+...+5(-2)^7=

9
∑ (1/4i)=
i=1




Respuesta :

Answer:

First equation is -425

Second equation is 11.25

Step-by-step explanation:

First equation we can write as

[tex]\sum_{i=0}^7 5 \times (-2)^i[/tex]

computing

When i=0 -> [tex]5 \times (-2)^0 =5[/tex]

When i=1 -> [tex]5 \times (-2)^1 = -10[/tex]

...

When i=7 -> [tex]5 \times (-2)^7 = --640[/tex]

then replacing each term we have

[tex] 5  + (-10) + ( 20) + ( -40) +  (80) +( -160) +   320 + (-640) = -425[/tex]

For the second equation we'll have 9 terms, solving in a similar fashion

When i=1 -> [tex]\frac{1}{4}1=0.25[/tex]

When i=2 -> [tex]\frac{1}{4}2=0.50[/tex]

When i=3 -> [tex]\frac{1}{4}3=0.75[/tex]

...

When i=9 -> [tex]\frac{1}{4}9=2.25[/tex]

So we have 0.25 + 0.50 + 0.75 + 1.00 + 1.25 + 1.50+ 1.75 +2.00 +2.25

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