1.выполни деление
а)) 3/4 : 2/5= 3/4• 5/2 = 15/8= 1 7/8
Б)) 4 2/7 : 11/10=
(4•7+2)/7 • 10/11= 30/7• 10/11=
300/77= 3 69/77
3)) найдите значение выражения
{ 4 1/3 - (2/5)^2 + 3 1/75} : 4/75=
{ 4 (1•25)/(3•25) - (2•2)/(5•5) + 3 1/75}• 75/4=
{ 4 25/75 - 4/25+ 3 1/75}•75/4=
{ 7 26/75 - (4•3)/(25•3)}• 75/4=
{ 7 26/75- 12/75}• 75/4=
7 14/75• 75/4=
(7•75+14)/75• 75/4=
539/75• 75/4=
Сокращаем 75 и 75 на 75;
539/1• 1/4= 539/4= 134 3/4.
Или так быстрее , если в десятичных можно
{ 4 1/3 - (2/5)^2 + 3 1/75} : 4/75=
(4•3+1)/3• 75/4- 4/25• 75/4+ (3•75+1)/75• 75/4=
13/3• 75/4- 4/25• 75/4+ 226/75• 75/4=
13/1• 25/4- 1/1• 3/1+ 113/1• 1/2=
13• 25/4- 3+ 113/2=
13• 6 1/4- 3+ 56 1/2=
56,5 - 3+ 13• 6,25=
53,5+ 81,25= 134,75
4)) решите уравнение
{ 3 1/2 + (2/3)^2 } • Х + 3/18= 5/18
{ 3 1/2+ (2•2)/(3•3)} • Х = 5/18- 3/18
{ 3 1/2+ 4/9} • Х = 2/18
Сокращаем 2/18 на 2
{ 3 (1•9)/(2•9) + (4•2)/(9•2)} • Х = 2/18
{ 3 9/18+ 8/18}• Х= 2/18
3 17/18• Х= 2/18
(3•18+17)/18• Х= 2/18
71/18•Х = 2/18
Х= 2/18: 71/18
Х= 2/18• 18/71
Х= 2/1• 1/71
Х= 2/71
Проверка
{ 3 1/2 + (2/3)^2 } • Х + 3/18= 5/18
{ 3 1/2+ 4/9}• 2/71+ 3/18 = 5/18
{ 3 9/18+ 8/18}•2/71+ 3/18=5/18
3 17/18• 2/71+ 3/18= 5/18
(3•18+17)/18 • 2/71+ 3/18=5/18
71/18• 2/71+ 3/18=5/18
1/18• 2/1+ 3/18= 5/18
2/18+3/18=5/18
5/18=5/18