8; 4

S5-?

1,5; 3

S5-?

В4=1/16

В5=1/64

S5-?

q=-2/3

S4=65

B1=?

1)

b1=8, b2=4

q=4/8=0,5

S5=a1 * (q^n-1) * 5/q-1=8 * (0,5^5-1) * 5/0,5-1=77,5

2)

b1=1,5. b2=3

q=3/1.5=2

S5=a1 * (q^n-1) * 5/q-1=1.5 * (2^5-1) * 5/2-1=232,5

В4=1/16

В5=1/64

q=1/64:1/16=1/4

a1=a4/q^3=4

S5=a1 * (q^n-1) * 5/q-1=4 * (1/4^5-1) * 5/1/4-1 = - 6