Question

$( \frac{1}{3} a - 2b)( \frac{1}{3}a+ 2b)$
$(0.3 - m)(m + 0.3)$
$(0.2a + 0.5x)(0.2a - 0.5x)$
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Answer 1

$( \frac{1}{3} a - 2b)( \frac{1}{3} a + 2b) \\ ( \frac{1}{3}a ) {}^{2} - (2b) {}^{2} \\ \frac{1}{9} a {}^{2} - 4b {}^{2}$

$(0.3 - m)(0.3 + m) \\ 0.3 { {}^{2} } - m {}^{2} \\ 0.09 - m {}^{2}$

$(0.2a + 0.5x)(0.2a - 0.5x) \\ 0.2 {}^{2} \times a {}^{2} - 0.5 {}^{2} \times x {}^{2} \\ 0.04a {}^{2} - 0.25x {}^{2}$