Question

can you explain first two line and how 1-10/100=90/100 and here some mistake also so please answer and correct it

Answer 1

$1 - \frac{10}{100} \\ just \: assume \: 1 \: as \: \frac{1}{1} \: now \\ \: think \: what \: you \: were \: did \: when \\ \: adding \: and \: subtracting \\ \: fractional \: numbers. \\ we \: take \: lcm \\ so \: lcm \: of \: 1 \: and \: 100 \: will \: be \: \: 100. \\ \frac{100 - 10}{100} = \frac{90}{100}$