Question

45+50+55+60+65calculati sumele folosind factorul comun

Answer 1

5 × ( 9 +10 +11 +12 +13) = 5 × 55 = 275

Answer 2

45=5·3·3

50=5·5·2

55=5·11

60=5·3·2·2

65=5·13

factor comun 5

45+50+55+60+65=5(9+10+11+12+13)=5*55=275