That do not make no sense to me.Use sigma notation to write the sum. -2.4-.4+1.6+3.6

By the formula's of arithmetical sequences:Find a formula for an for the arithmetic sequence. a1=7, a11=19

Substitute know values,

Thus,

Thus,

"An arithemtica sequnce with initial term of 7 and constant diffrence of 1.2"

Same idea.Find a formula for an for the arithmetic sequence. a1=11, a11=15

This is a geometric series because the situation is,A rubber ball on a hard surface takes a sequence of vertical bounces. Each bounce is 1/6 as high as the proceeding one. If this ball is dropped from a height of 12 feet, find the total distance it has traveled when it hits the surface the fifth time.

Thus,

---> Because you only got 5 bounces (do not think the exponent is 4 a common mistake it should be 4)

Thus, factor

Use sum for geometric series,

-2,4,0,-16,326. Write the first five terms of the sequence.

a0=-2

a1=4

an=-2a n -1-4an-2

Which term is that? The third thus,7. Find the coefficient of b6a2 in the expansion of (b+2a)8

Tooooooooooooooooooooooooo long.8. Use the binomial theorem to expand and simplify the expression.

(s-u)5

Order no important thus,

9. A college has seven instructors qualified to teach a special computer lab course which requires two instructors to be present. How many different pairs of teachers could teach the class.

Same as before,10. Eight cards are drawn, without replacement, from a standard deck of 52 cards. How many sets of eight cards are possible?

Not doing this one you promised only 10.11.