Question

Прощу помощи помогите пж надо срочно

Answer 1

1)

а) $(2+sqrt{3})*(1-sqrt{3} ) = 2-2sqrt{3} + sqrt{3} -3 = -1-sqrt{3}$

б) $(a+sqrt{c})*(a-sqrt{c}) = a^{2} -sqrt{c}^{2} = a^{2} - c$

в) $(1+3sqrt{2}) * (3sqrt{2}  -1) = (3sqrt{2}+1)*(3sqrt{2}-1)=9*2-1=18-1=17$

г) $(1-2sqrt{3})^{2}=1-4sqrt{3}+12=13-4sqrt{3}$

2)

а) $frac{a^{2}-3 }{a+sqrt{3} }=frac{(a^{2}-3)*(a-sqrt{3})}{(a+sqrt{3})*(a-sqrt{3})  } = frac{(a^{2}-3) * (a-sqrt{3})  }{a^{2}-3}=a-sqrt{3}$

б) $frac{sqrt{7}-y }{7-y^{2} } = frac{sqrt{7} -y}{(sqrt{7}-y) * (sqrt{7} +y) } = frac{1}{sqrt{7} +y}$

в) $frac{5-sqrt{5} }{sqrt{5} }=frac{(5-sqrt{5})sqrt{5}  }{sqrt{5} sqrt{5} } = frac{5sqrt{5} -5}{5} = frac{5(sqrt{5}-1) }{5} = sqrt{5} -1$

г) $frac{sqrt{b}-sqrt{c}  }{b-c}= frac{sqrt{b}- sqrt{c} }{(sqrt{b} -sqrt{c})*(sqrt{b}  + sqrt{c}) } = frac{1}{sqrt{b} +sqrt{c} }$