Question

if on A.p. d=-4, n=7 an=4 then find a 1st term guys please answer fast​

Answer 1

Answer:

an=4

d=(-4)

n=7

an=a+(n-1)d

4=a+(7-1)(-4)

a=4+24=28

a=28

FIRST TERM IS 28....

Answer 2

Given:-

• d = -4
• n = 7
• $\sf a_{n}$ = 4

To find:-

• value of 1st term. i.e (a)

Formula:-

$\underline{\boxed{\sf a_{n} = a+(n-1)d}}$

Solution:-

$\longrightarrow$ $\sf a_{n}$ = a+(n-1)d

$\longrightarrow$ 4 = a+(7-1)-4

$\longrightarrow$ 4 = a+(6)-4

$\longrightarrow$ 4 = a-24

$\longrightarrow$ a = 28.

hence, the value of 1st term is 28.

Additional information:-

in order to find sum of n terms of an A.P following formula is used:-

$\sf S_{n}$ = $\sf\dfrac{n}{2}$ × $\sf {{2a+(n-1)d}}$