Question

Find the sum of first 32 terms of an ap whose nth term is 5-2n

Answer 1

Nth teen = an= 5-2n

Let n =1

A=5-2(1)

a=3

a2=a+d

a2=5-2(2)

a 2=5-4=1

D=a2-a1

D=1-3=-2

Sn=n/2(2a+(n-1)d)

S32=32/2(2(3)+(32-1)-2)

S32=16(6-62)

S32=16(-56)

S32=-896

Answer 2

Answer:

Step-by-step explanation:

first term,

5-2n

=5-2[1] = 3

a= 3

t2  = 5-2[2]=1

d = t2- t1= 1-3 = -2

S32= 32/2[2*3 + 32-1*-2]

=16[6- 62]

= 16[ -51]

= -896