Question

If 4/5 x blank = 2/5 what is blank

Answer 1

`(4)/(5)\cdot\fbox{\ }=(2)/(5)\ \ \ \ /\cdot(5)/(4)\\\\(\\ot5^1)/(\\ot4_1)\cdot(\\ot4^1)/(\\ot5_1)\cdot\fbox{\ }=(\\ot5^1)/(\\ot4_2)\cdot(\\ot2^1)/(\\ot5_1)\\\\\fbox{\ }=(1)/(2)`

Answer 2

`(4)/(5) \cdot x = (2 )/(5) \ \ /\cdot 5\\ \\ \\ot5^(1)\cdot (4)/(\\ot5^(1)) \cdot x =\\ot5^(1 ) \cdot (2 )/(\\ot5^(1))\\ \\4x=2 \ \ /:4 \\ \\x=(2)/(4)\\ \\x=(1)/(2)`