Answer:
S=157
Step-by-step explanation:
an= a1+(n-1)d
a2=80+(2-1)(-3)
a2=80-3
a2=77
Sn=(a1+an)*n/2
S2=(80+a2)*2/2
S2=(80+77)*1
S2=157
Answer:
8
Step-by-step explanation:
Answer: 7 × ( 3^n - 1 )
Step-by-step explanation:
This is a geometric progression which has its nth term to be
Tn = ar^n- 1. Now from the question given, the sequence are 7, 21, 63, 189. This is an example of a finite sequence, To find the common ratio, you divide the second term by the first term. So
r = 21/7
= 3. , a = 7
Now to find the nth term put the values in the formula above.
Tn =ar^n-1
= 7(3)^n - 1)
= 7 × ( 3^n - 1 ).
Note, it is not 21^n - 1.
Answer:
Ice Cube, Liquid Water, and Steam
Step-by-step explanation:
An example of a solid is a ice cube, the particles are compacted together and there's very little movement.
An example of a liquid is water, the particles are more spread around and the movement is more frequent.
An example of a gas is steam, the particles are anywhere, moving fast and sporadic.
Answer:
Step-by-step explanation:
5
−322
=
5
−1024
=
−5
1024
