Find a recursive formula for the sequence:

Step-by-step explanation:

Successive terms do not have a common difference or ratio, so the sequence is not arithmetic or geometric. We can get a clue as to its nature a couple of places:

It is helpful to look at the differences of terms:

  -5-3 = -8

  11 -(-5) = 16

  -21-11 = -32

These have a common ratio of -2, so match an exponential form with a ratio of -2 (the last answer choice). Trying that choice with n=1, 2, 3, 4 gives ...

  a[1] = 3

  a[2] = -2(3) +1 = -5

  a[3] = -2(-5) +1 = 11

  a[4] = -2(11) +1 = -21

These match the given sequence, so the appropriate recursive formula is ...

Step-by-step explanation:

irrational, cannot

26 is 33.33% of 78

step-by-step explanation:

26 is what percent of 78?

26 is p% of 78

equation: y = p% * x

solving our equation for p

p% = y/x

p% = 26/78

p = 0.3333

convert decimal to percent:

p% = 0.3333 * 100 = 33.33%