Final answer:
To find the 11th term of the geometric sequence 5, -20, 80, -320, you can use the formula a_n = a_1 * r^(n-1), where a_n is the nth term, a_1 is the first term, and r is the common ratio. Plugging in the values, the 11th term is 5242880.
Step-by-step explanation:
To find the 11th term of the geometric sequence 5, -20, 80, -320, we can use the formula for a geometric sequence:
an = a1 * r(n-1)
where an is the nth term, a1 is the first term, and r is the common ratio.
In this case, the first term is 5, and the common ratio is -4. So, we have:
a11 = 5 * (-4)(11-1)
Simplifying,
a11 = 5 * (-4)10
Calculating the value, a11 = 5 * 1048576 = 5242880