Question

[tex]( sqrt15 + sqrt5)* sqrt15- frac53* sqrt27= 

Answer 1

$( sqrt15 + sqrt5)* sqrt15- frac53* sqrt27=15+ sqrt{5} cdot sqrt{5cdot 3} - dfrac{5}{3} cdot sqrt{9cdot 3} =\\=15+5 sqrt{3} -5 sqrt{3} =15$

Answer 2

http://znanija.com/task/6694785 помогите)

Answer 3

$( sqrt15 + sqrt5)* sqrt15- frac53* sqrt27= sqrt{75}+ sqrt{25}- frac{5 sqrt{27} }{3} = sqrt{25*3}+ sqrt{25} - frac{5 sqrt{9*3} }{3}=5 sqrt{3}+5- frac{5*3 sqrt{3} }{3}=5 sqrt{5}+ 5 +5 sqrt{3}=5( sqrt{5}+ sqrt{3}+1)$