Question

If a and b are positive integers such that asquare is b then (a-b)square a+b-4 is equal to

Answer 1

${a }^{2} = b \: {given}$
$( {a - b) \:}^{2} a + b - 4$
${a}^{2} + {b}^{2} - 2ab ( a + b - 4)$
${b}^{2} + b - 2ab ( a + b - 4)$