Question

Help ı need to solv thıs worksheet

Answer 1

130, - 12, 56.1, 11.2

these are all arithmetic sequences with n th term formula

$a_{n}$ = $a_{1}$ + (n - 1 )d

where d is the common difference and $a_{1}$ the first term

(1)

d = 10 - 4 = 4 - (- 2 ) = 6 and $a_{1}$ = - 14

$a_{25}$ = - 14 + (24 × 6) = - 14 + 144 = 130

(2)

d = 14 - 16 = 16 - 18 = - 2 and $a_{1}$ = 22

$a_{18}$ = 22 + (17 × - 2 ) = 22 - 34 = - 12

(3)

$a_{50}$ = 2.2 + (49 × 1.1) = 2.2 + 53.9 = 56.1

(4)

$a_{12}$ = - 4.2 + (11 × 1.4 ) = - 4.2 + 15.4 = 11.2