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A.P. = 3,8,13........253Find last 20th term..? |
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Answer» As it is given from laat so, a=253d= (-5)a20 = ? an a+(n-1)da20= 253+(20-1)(-5) = 253+(19)(-5) =253-95 158Therefore 20th term of an AP from last is 158 Write this in given form 253.......13,8,3Here, a= 253 and d=8-3 =-5An = 253+(20-1)(-5)=253 +19*(-5) = 253-95= 158 3,8,13.......,253To find 20th term form the last term we consider the sequence as followsa = 253 and d = 3 - 8 = -5an\xa0= a + (n - 1)da20\xa0= a + (20 - 1)d = 253 + 19\xa0×\xa0(-5) = 253 - 95 = 158Hence, the 20th term from the last term is 158. 158 |
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