Select the correct answer.
what is the value of (4 x (1/2)-1).
what is the value of t=1

For this case we must substitute the values t = 1,2,3 in the given series:

For

For :

For :

We add:

So, the value is 7.

Option C

Option C.

Step-by-step explanation:

The given expression is

We have to find the sum of 3 terms of the sequence formed.

The given sequence is a geometric sequence.

Explicit formula for this sequence is in the form of

In the given formula first term a = 4

and common ratio r =

Sum of a geometric sequence is represented by the expression,

Therefore, Option C is the answer.

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15