Question

s10=...................................... if a=3,d=5?​

Answer 1

Answer:

255

Step-by-step explanation:

a=3;d=5; n=10.................(given)

l(last term)= ?

l = a+(n-1)d

l= 3+(10-1)5

l= 3+9x5

l= 48

Now,

Sn= n/2[a+l]

=10/2[3+48]

=5[51]

=255

Answer 2

Step-by-step explanation:

Formula=

• sn=n÷2[2×a+(n-1)×d]
• s10=10÷2[2×3+(10-1)×5]
• s10=5[6+9×5]
• s10=5[6+45]
• s10=5×[51]
• s10=255