find a under n for the following geometric sequence. a ubder 1 =5,r = - 2. so a under n = ( ) n-1.

To find the value of "a" for the nth term in a geometric sequence, you can use the formula:

a_n = a_1 * r^(n-1)

Given that a_1 = 5 and r = -2, we can substitute these values into the formula:

a_n = 5 * (-2)^(n-1)

Therefore, a_n = 5 * (-2)^(n-1).

To find the value of a sub n for the geometric sequence, we need to use the formula for the nth term of a geometric sequence. The formula is given as:

a sub n = a sub 1 * (r)^(n-1)

Given:
a sub 1 = 5
r = -2

We can substitute these values into the formula to find a sub n:

a sub n = 5 * (-2)^(n-1)

Therefore, a sub n is equal to 5 multiplied by -2 raised to the power of (n-1).