Question

Qestion no 1 the thenth trem of an arithmetic sequence is 20 and its twentieth term is 10 (a ) what is the common difference (b) what is the first term? (C) write the sequence​

Answer 1

Answer:

a) common difference d = 1

b) first term a = 29

Step-by-step explanation:

10th term = 20

12th term = 10

nth term = a+(n-1)d = a+nd-d

10th term = a+10d-d = 20 eq 1

20th term = a+20d-d = 10 eq2

eq 1 a-9d=20

eq 2 a-19d=10

eq1 - eq2

10d = 10

d = 1

sub d=1 in eq1

a-9=20

a=20+9

a=29