Question

Ex 6,7 dau coroana pentru raspunsul corect si intreg!

Answer 1

Răspuns:

Explicație pas cu pas:

6.

b1 = 32

q = 1/2

b2 = 32*1/2 = 16

b3 = 16*1/2 = 8

b4 = 8*1/2 = 4

_____________

7.

r = a2 - a1 = 9 - 7 = 2

a7 = a1 + 6r = 7 + 6*2 = 7 + 12 = 19

Answer 2

$\displaystyle 6.~~b_1=32,~q=\frac{1}{2} ,~b_4=?\\\\ b_n=b_1\cdot q^{n-1}\\\\ b_4=32 \cdot \Bigg(\frac{1}{2} \Bigg)^{4-1}=32 \cdot \Bigg(\frac{1}{2} \Bigg)^3=32 \cdot \frac{1^3}{2^3} =32 \cdot \frac{1}{8} =\frac{32}{8} =4$

$7.~~a_1=7,~a_2=9,~a_7=?\\\\ a_n=a_1+(n-1)\cdot r\\\\ a_2=9 \Rightarrow a_1+r=9 \Rightarrow 7+r=9\Rightarrow r=9-7\Rightarrow r=2\\\\ a_7=a_1+(7-1) \cdot r=7+6 \cdot 2=7+12=19$