Tolong bantuin dongg

[tex]22. \: \: {( \sqrt{a} - \sqrt{b} )}= \sqrt{(a + b) - 2 \sqrt{ab} } = \sqrt{11 - 2 \sqrt{28} } \\ a + b = 11 \: \: \: \: b = 11 - a\\ - 2 \sqrt{ab} = - 2 \sqrt{28} \\ ab = 28 \\ a(11 - a) = 28 \\ {a}^{2} - 11a + 28 = 0 \\ (a - 7)(a - 4) = 0 \\ a = 7 \: \: atau \: \: a = 4 \\ b = 4 \: \: atau \: \: b = 7 \\ 2 - \sqrt{7} \: \: \: atau \: \: \: \sqrt{7} - 2[/tex]