# If s = n/2(2a+(n-1)d) find a) a, when s = 185 n = 10 and d = 3 b) d, when a = 8 s = 380 and n =10

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by Papa123

mentioning units is important dear,in questions especially as well as answers.

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by Papa123

mentioning units is important dear,in questions especially as well as answers.

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A) 185=10/2(2a+(5-1)3)

= 5(2a+(4*3))

= 10a+60 (4*3=12; nd 12*5=60)

185-60=10a

125/10=a

∴a=12.5

= 5(2a+(4*3))

= 10a+60 (4*3=12; nd 12*5=60)

185-60=10a

125/10=a

∴a=12.5