Question

2,54+2,54•2+2,54•3+....+2,54•11
trebuie sa scoatem factor comun
ajutatima

Answer 1

2,54(1+1*2+1*3+.....1*11) = 
2,54(1+2+3+...11) = 
2,54($\frac{11+12}{2}$) = 
2,54($\frac{23}{2}$) = 
2,54 * 11,5 = 29,21