Помогите решить 1 b, 2, 4 b

1b
$\sqrt[3]{(4+2 \sqrt{2})(4-2 \sqrt{2} ) } = \sqrt[3]{16-8} = \sqrt[3]{8} =2$
2a
$a ^{-3} *a^2b ^{2/3} /b ^{1/3} =a ^{-1} b ^{1/3} = \sqrt[3]{b} /a$
2b
$(a ^{1- \sqrt{2} } ) ^{ \sqrt{2} +1} *a ^{ \sqrt{2}+1 } =a ^{1-2+ \sqrt{2} +1} =a ^{ \sqrt{2} }$
4b
2/3<1⇒<img src="https://tex.z-dn.net/?f=%282%2F3%29+%5E%7B+%5Csqrt%7B2%7D+%7D+%5C+%5Ctextless+%5C+1" id="TexFormula4" title="(2/3) ^{ \sqrt{2} } \ \textless \ 1" alt="(2/3) ^{ \sqrt{2} } \ \textless \ 1" align="absmiddle" class="latex-formula">