Question

Выполните умножение: а) 9/10 * 5/6; д) 57/37 * 74/86; и) 5/13 * 39; н) 2 14/15 * 6 6/11; б) 6/25 * 20/21; е) 81/115 * 46/81; к) 5 * 2 1/5 о) 2 2/25 * 1 9/16; в) 17/30 * 26/51; ж) 3/16 * 4; л) 3 3/5 * 1 1/9; п) 13/43 * 8 7/26г) 40 * 14/5; з) 23 * 5/46; м) 4 2/7 * 2; 

Answer 1

Выполните умножение:

а) 9/10 * 5/6= 3/2• 1/2= 3/4
{Сократили, значит поделили; 9 и 6 на 3; 10 и 5 на 5}

д) 57/37 * 74/86= 57/1• 2/86= 114/86= 1 28/86= 1 14/43
{сократили 37 и 74 на 37; 28/86 на 2}

и) 5/13 * 39= 5/13• 39/1= 5/1• 3/1= 15 {сократили 13 и 39 на 13}

н) 2 14/15 * 6 6/11= (15•2+14)/15 • (11•6+6)/11= 44/15 • 72/11= 4/5• 24/1= 96/5= 19 1/5
{сократили 44 и 11 на 11; 15 и 72 на 3}

б) 6/25 * 20/21= 2/5• 4/7= 8/35
{сократили 25 и 20 на 5; 6 и 21 на 3}

е) 81/115 * 46/81= 1/5• 2/1= 2/5
{сократили 81 и 81 на 81; 115 и 46 на 23}

к) 5 * 2 1/5 = 5/1• (5•2+1)/5= 5/1• 11/5= 1/1• 11/1= 11
{сократили 5 и 5 на 5}

о) 2 2/25 * 1 9/16= (25•2+2)/25 • (16•1+9)/16= 52/25 • 25/16= 13/1• 1/4= 13/4= 3 1/4
{сократили 25 и 25 на 25; 52 и 16 на 4}

в) 17/30 * 26/51= 1/15• 13/3= 13/45
{сократили 17 и 51 на 17; 30 и 26 на 2}

ж) 3/16 * 4= 3/16• 4/1= 3/4• 1/1= 3/4
{сократили 16 и 4 на 4}

л) 3 3/5 * 1 1/9= (5•3+3)/5 • (9•1+1)/9= 18/5• 10/9= 2/1• 2/1= 4
{сократили 18 и 9 на 9; 5 и 10 на 5}

п) 13/43 * 8 7/26= 13/43 • (26•8+7)/26= 13/43 • 215/26= 1/1• 5/2= 5/2= 2 1/2
{сократили 13 и 26 на 13; 43 и 215 на 43}

г) 40 * 14/5= 40/1• 14/5= 8/1• 14/1= 112
{сократили 40 и 5 на 5}

з) 23 * 5/46= 23/1• 5/46= 1/1• 5/2= 5/2= 2 1/2
{сократили 23 и 46 на 23} м) 4 2/7 * 2= (7•4+2)/7 • 2/1= 30/7• 2/1= 60/7= 8 4/7

Answer 2

а) 9/10 * 5/6 = (9 * 5) / (10 * 6) = 45/60 = 3/4

д) 57/37 * 74/86 = (57 * 74) / (37 * 86) ≈ 4206/3182 ≈ 2103/1591

и) 5/13 * 39 = (5 * 39) / 13 = 195/13 = 15

н) 2 14/15 * 6 6/11 = (2 * 15 + 14/15) * (6 * 11 + 6/11) = (30 + 14/15) * (66 + 6/11) = (450/15 + 14/15) * (726/11 + 6/11) = (464/15) * (732/11) = 213888/7425 ≈ 28.8

б) 6/25 * 20/21 = (6 * 20) / (25 * 21) = 120/525 = 8/35

е) 81/115 * 46/81 = (81 * 46) / (115 * 81) = 3726/9325 ≈ 0.3993

к) 5 * 2 1/5 = 5 * (2 + 1/5) = 10 + 1 = 11

о) 2 2/25 * 1 9/16 = (2 * 25 + 2/25) * (1 * 16 + 9/16) = (50 + 2/25) * (16 + 9/16) = (1250/25 + 2/25) * (256/16 + 9/16) = (1252/25) * (265/16) = 331180/400 ≈ 827.95

в) 17/30 * 26/51 = (17 * 26) / (30 * 51) ≈ 442/765

ж) 3/16 * 4 = (3 * 4) / 16 = 12/16 = 3/4

л) 3 3/5 * 1 1/9 = (3 * 5 + 3/5) * (1 * 9 + 1/9) = (15 + 3/5) * (9 + 1/9) = (75/5 + 3/5) * (82/9 + 1/9) = (78/5) * (83/9) = 20274/45 ≈ 450.53

п) 13/43 * 8 7/26 = (13/43) * (8 + 7/26) = (13/43) * (208/26 + 7/26) = (13/43) * (215/26) = 280/43 ≈ 6.512

г) 40 * 14/5 = (40 * 14) / 5 = 560/5 = 112

з) 23 * 5/46 = (23 * 5) / 46 ≈ 115/46 ≈ 2.5

м) 4 2/7 * 2 = (4 * 7 + 2/7) * 2 = (28 +