(2 1/3 + 0,25 ) * 0,12 = 0,31
1) 2 1/3 + 0,25 = 2 1/3 + 25/100 = 2 1*100/3*100 + 25*3/100*3 = 100/300 + 75/300 = 2 100+75/300 = 2 175/300 = 2 7/12
2) 2 7/12 * 0,12 = 2 7/12 * 12/100 = 2 7/12 * 3/25 = 31/12 * 3/25 = 93/300 = 31/100 = 0,31
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( 7,6 - 4 3/7 ) : 1,9
1) 7,6 - 4 3/7 = 7 6/10 - 4 3/7 = 3 6/10 - 3/7 = 3 42/70 - 30/70 = 3 12/70 = 3 6/35
2) 3 6/35 : 1,9 = 3 6/35 : 1 9/10 = 111/35 : 19/10 = 111/35 * 10/19 = 1110/665 = 222/133 = 1 89/133