Question

3÷1/3
5÷1/2
4÷1/3
5÷1/4​

Answer 1

$3 \div 1 \: by \: 3 \\ = 3 \times 3 \: (reciprocal) \\ = 9 \\ next \\ 5 \div 1 \: by \: 2 = 5 \times 2 = 10 \: \\ next \:$

$4 \div 1\: by \: 3 = 4 \times 3 \\ = 12 \: (answer) \: \\ 5 \div \: 1 \: by \: 4 \\ = 5 \times 4 \\ = 20 \: (answer)$

$all \: these \: are \: \\ reciprocal \: sums \: just \\ turn \: them \: upside \\ down \: and \: multiply \: \\ and \: you \: are \\ good \: to \: go \: \\ hope \: it \: helps$

Answer 2

$\huge\colorbox{purple}{Answer}$

$1) \: 3 \times \frac{3}{1} = 9 \\ \\ 2) \: 5 \times \frac{2}{1} = 10 \\ \\ 3) \: 4 \times \frac{3}{1} = 12 \\ \\ 4) \: 5 \times \frac{4}{1} = 20$