Which of the following is the general term for the sequence
-a, a2, -a3, a4, 15
choices:
a) a(-1)n - 1
b) -a(-a)n-1
c) (-1)an + 1
d.) (-a)n + 1

This is an example of a geometric sequence.  To find for the nth term, we use the formula:

an = a1 r^(n – 1)               ---> 1

Where:

a1= 1st term of the sequence = -a

r = common ratio

To find for the common ratio r, we divide the 2nd term with the 1st term (we can also divide the 3rd term with the 2nd term; we can use any 2 terms as long as they are in succession.)

r = a^2 / -a

r = -a

Substituting a1 and r in equation 1:

an = -a (-a)^(n-1)

Therefore the B) -a(-a)n-1

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b

i those same problems in math and dont know how to do them