Question 1091746
sum is (n/2)(a1+an)
a1=10
an is a1+(n-1)d
a1=10
n-1=29
d=-5
a30=10+29(-5)=-135
S=(30/2)(10-135)=15(-125)=-1875
10
5
0
+ terms are +15
-5
-10
-15
-20
-25
-30
-35
-40
-45
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-55
-60
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-75
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-85
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-105
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-125
-130
-135