Question

the first terms of an ap is 5 the last terms is 45 and the sum is 400 find the number of terms and the common differece​

Answer 1

Answer:

a=5

an=45

s=400

s=n/2 (a+an)

400=n/2 (5+45)

400×2=n(50)

n (50)=800

n=800/50

n=16

so,

an=a+(n-1)d

45=5+(16-1)d

45-5=15d

15d=40

d=40/15

d=8/3

Answer 2

Here your answer friend