Question

Calculați următoarele sume 5 plus 10 plus 15 plus puncte puncte plus 2000
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Answer 1

5+10+15+...2000=

n=(u-p):r+1

n=(2000-5):5+1

n=1995:5+1

n=399+1

n=400

S=(u+p)×n:2

S=(2000+5)×400:2

S=2005×400:2

S=2005×200

S=802000