4/9*х=3,6
х=3,6:4/9
х=3целых 6/10 :4/9
х=3*10+6/10 :4/9
х=36/10:4/9
х=36/10*9/4
х=36*9 / 10*4 (сократим 36 и 4)
х=9*9 / 10*1
х=81/10
х=8целых 1/10
проверка
4/9*х=3,6
4/9*8ц1/10=3,6
<span>4/9 * 8*10+1/10</span><span />=3,6
<span>4/9 * 81/10</span><span />=3,6
<span>81*4 / 10*9</span>=<span>3,6
324/90</span>=<span>3,6 (сократим 324 и 90 на 18)
</span><span>18/5</span>=3,6
18:5=3,6
3,6 = <span>3.6</span>
4/9 * x = 3,6,
x = 3,6 : 4/9,
x = 36/10 * 9/4,
x = 81/10,
x = 8,1