how many terms of the ap:-6,-11/2,-5 are needed to give a sum of -25? Explain the double answer
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Answered by
3
sum = n/2( a + l)
- 25 = n/2 ( -12+ (n-1) (1/2) )
n² - 25 n + 100 = 0
n = 20 or n = 5
- 25 = n/2 ( -12+ (n-1) (1/2) )
n² - 25 n + 100 = 0
n = 20 or n = 5
Smitmodi:
bro its not -6 its -12
its n/2(2a+(n-1)d)
Answered by
4
after putting the formula of Sum of AP you will get an quadratic equation "n*n -25n+100=0"
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