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Work Shown:
term1 = 2
term2 = -10
term3 = 50
term4 = -250
term5 = 1250
term6 = -6250
Each new term is found by multiplying the previous term by -5
Add up the terms
2 + (-10) + 50 + (-250) + 1250 + (-6250) = -5208
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A shortcut is to use a = 2, r = -5 and n = 6 in the formula below
Sn = a*(1-r^n)/(1-r)
S6 = 2*(1-(-5)^6)/(1-(-5))
S6 = 2*(1-15625)/(1+5)
S6 = 2*(-15624)/6
S6 = -31248/6
S6 = -5208
