u19=-71.74
Step-by-step explanation:
u5=a+4d=-3.7....(1)
u15=a+14d=-52.3....(2)
-10d=48.6
d=-48.6/-10
d=-4.86
Substitute-4.86 into....(1)
u5=a+4(-4.86)=-3.7
a+(-19.44)=-4.7
a=-3.7-(-19.44)
a=15.74
19term=a+18d=?
=15.74+18(-4.86)
=15.74+(-87.48)
19th term =-71.74
