Question

Make the letter in square brackets the subject

Answer 1

Answer:

$given \sqrt{(x {}^{2} + a)} = 2x \\ \: solution \: \\ or x { }^{2} + a = 4x { }^{2} \\or3x ^{2} = a \\ or \: x ^{2} = a \div 3 \\ or \: x = \sqrt{a \div 3} ans$