# Mathematics

If the 2nd and 5th term of a g.p are -6 and 48 respectively.Find the sum of the first four terms

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1. https://www.mathsisfun.com/algebra/sequences-sums-arithmetic.html
a+d = -6
a+ 4d = 48
---------------
-3 d = -54
d = 18
a + 18 = -6
a = -24
so
-24 , -6 , 12 , 30 , then 48 is next

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Damon
2. Whoops sorry, thought ap but you said gp
https://www.mathsisfun.com/algebra/sequences-sums-geometric.html
a , a r , a r^2 , a r^3 , a r^4
a r = -6
a r^4 = 48
so
-6 r^3 = 48
r^3 = -8
r = -2
then a = 3
continue as before

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Damon

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