Question

t3=22 and t17=-20 find the tn

Answer 1

t3=22-->a+2d=22----(1)
t17=-20-->a+16d=-20---(2)
(1)-(2)=2d-16d=20-(-20)
-14d=20+20
d=40÷-14
d=-(20/7)
sub. in (1) then a=22-(-20/7)=(154+20)/7
a=174/7
so tn=a+(n-1)d
=(174/7)+(n-1)(-20/7)
=(174-20n+20)/7
so
$tn = \frac{194 - 20n}{7}$
hope it'll help
mark it as brainliest