a)

$6^2=36,\text{zatem}\sqrt{36}=6$

czyli

$x=36$

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b)

$8^2=64,\text{zatem}\sqrt{64}=8$

czyli

$x=64$

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c)

${\left(\frac{3}{7}\right)}^2=\frac{9}{49},\text{zatem}\sqrt{\frac{9}{49}}=\frac{3}{7}$

czyli

$x=\frac{9}{49}$

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d)

$(0,2{)}^2=0,04,\text{zatem}\sqrt{0,04}=0,2$

czyli

$x=0,04$

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e)

${\left(1\frac{1}{2}\right)}^2={\left(\frac{3}{2}\right)}^2=\frac{9}{4}=2\frac{1}{4},\text{zatem}\sqrt{\frac{9}{4}}=\frac{3}{2}=1\frac{1}{2}$

czyli

$x=2\frac{1}{4}$