a)=25-12+16-8√5+5+8√5=34
b)=3*4√3-5√3+1/7*7√3=12√3-5√3+√3=6√3
[tex]c) \frac{ \sqrt{6}( \sqrt{2}-1 ) }{ \sqrt{15}( \sqrt{2}-1) } = \frac{ \sqrt{6} }{ \sqrt{15} }= \frac{ \sqrt{90} }{15} = \frac{3 \sqrt{10} }{15} = \frac{ \sqrt{10} }{5} \[/tex]
[tex]d) \sqrt[4]{6x(5+2 \sqrt{6})(3 \sqrt{2x}-2 \sqrt{3x})^2 } = \\ \sqrt[4]{6x(5+2 \sqrt{6})(18x-12x \sqrt{6}+12x) }= \sqrt[4]{6x(5+2 \sqrt{6})(30x-12x \sqrt{6}) } = \\ = \sqrt[4]{6x(5+2 \sqrt{6})6x(5-2 \sqrt{6}) }= \sqrt[4]{36x^2(25-24)}= \\ = \sqrt[4]{36 x^{2} } = \sqrt[4]{(6x)^2}= \sqrt{6x} [/tex]
d)=(1+3√5+15+5√5)(2+√5)=
=(16+8√5)(2+√5)=8(2+√5)²=8(4+4√5+5)=8(9+4√5)
