Question

How many terms of an ap must be taken to sum their 180 .whether ap is 45,39,33

Answer 1

Answer:

a=45  ,   d= -6    an= -180

we know that a+(n-1)d=an

= 45+(n-1)-6=-180

=(n-1)-6=-180-45

=(n-1)-6=-225

=(n-1)=225/6

=n=37.5+1

=n=38.5 ans

mark brainlist plzz

Answer 2

Answer:

10,6

Step-by-step explanation:

AP = 45,39,33...

we know,

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

here, Sn=180  ,  a=45   ,  d=-6

putting the values in formula,

180 = n/2[2(45)+(n-1)-6]

180 = n/2[90-6n+6]

180 = n/2[96-6n]

180 = n/2*2[48-3n]

180 = 48n-3n²

3n²-48n+180 = 0

(dividing whole equation by 3)

n²-16n+60

by splitting the mid-term

=(n²-10n)(-6n+60)

=n(n-10)-6(n-10)

=(n-10)(n-6)

n=10,6

AP can have 10 or 6 terms.

HOPE IT HELPED YOU!!!

MARK AS BRAINLIEST!!!

HAVE A GREAT DAY :)