Răspuns:
1+2+3+4...=50supra
2+4+6...+100=xsupar 4
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2+4+6...+100=5100
1.numărul termenilor=>(100-2):2+1= 98:2+1=5100
2.suma=>50×(100+2)=50×102=5100
×=5100 supra 4
Formulele pe care le-am folosit
nr termenilor =(nr mare-nr mic ) :2 +1
suma=nr termenilor ×(nr mare+nr mic):2
