1) 17 / 50 si 7 /20 stabilim numitorul comun 20 = 2²·5 50 = 2·5² ================ numitorul comun = 2²·5² = 100 NC =100 ================== 17·2 / 100 si 7·5 /100 34/ 100 si 35/100 ⇒ 34 < 35 ⇒ 34/100 < 35/100 ⇒ 17/50 < 7/20 2) 4/9 si 3 / 8 9 = 3² 8 = 2³ ============= NC = 2²·3² = 8 · 9 = 72 ================== 4·8 / 72 SI 3·9 / 72 32 / 72 SI 27 / 72 ⇒ 32 > 27 ⇒ 32/72 > 27 /72 4 / 9 > 3/8 3) 21 /23 SI 14/ 13 23 = 23 13 = 13 =============== NC = 13·23 = 299 ============== 21·13/ 299 SI 14·23 /299 273/ 299 SI 322/ 299 ⇒ 273 < 322 ⇒ 273/299 < 322/299 21/23 < 14/13
[latex] frac{17}{50} [/latex] si [latex] frac{7}{20} [/latex] 17*20=340 si 7*50=350 340<350 [latex] frac{17}{50}< frac{7}{20} [/latex] 2)[latex] frac{4}{9} [/latex] si [latex] frac{3}{8} [/latex] 4*8=32 si 9*3=27 32>27 [latex] frac{4}{9}> frac{3}{8} [/latex] 3) [latex] frac{21}{23} [/latex] si [latex] frac{14}{13} [/latex] [latex] frac{21}{23}<1 [/latex] si [latex] frac{14}{13}>1 [/latex] [latex] frac{21}{23}< frac{14}{13} [/latex]