Question

решите уравнение : е) y:3 1/5 = 4 1/2: 2 1/4; ж) 1/5 x:5=16:0,8

Answer 1

1)у=135/16 =8 7/16 или 8, 4375

2)х=500

Вроде так)

Answer 2

Ответ:

е) y:3 1/5 = 4 1/2: 2 1/4;

$y:3\frac{1}{5}=4\frac{1}{2}:2\frac{1}{4} ;\\\\\frac{y}{3\frac{1}{5} } =\frac{4\frac{1}{2}}{2\frac{1}{4}};$

Перемножаем крест-накрест:

$y*2\frac{1}{4}=4\frac{1}{2}*3\frac{1}{5};\\\\y*\frac{4*2+1}{4} =\frac{2*4+1}{2} *\frac{5*3+1}{5} ;\\\\y*\frac{9}{4} =\frac{9}{2} *\frac{16}{5} ;\\\\\frac{9}{4}y=9*\frac{8}{5};\\\\\frac{9}{4}y=\frac{9*8}{5}; \\\\\frac{9}{4}y=\frac{72}{5}; |*\frac{4}{9} \\\\\frac{4}{9}*\frac{9}{4}y=\frac{4}{9}*\frac{72}{5};\\\\y=4*\frac{8}{5};\\\\y=\frac{4*8}{5} ;$

$y=\frac{32}{5}$   или  $y=6\frac{2}{5}$  или $y=6,4.$

ж) 1/5 x:5=16:0,8

$\frac{1}{5}x=16:0,8;\\\\\frac{1}{5}x=16:\frac{8}{10} ; \\\\\frac{1}{5}x=16:\frac{4}{5} ;\\\\\frac{1}{5}x=16*\frac{5}{4} ;\\\\\frac{1}{5}x=4*\frac{5}{1} ; \\\\\frac{1}{5}x=20; |*5\\\\5*\frac{1}{5}x=20*5;\\\\x=100.$