Question

Помогите пожалуйста! Срочно!!! Даю 20 баллов

Answer 1

Ответ:

1.

а)184

б)29

2.

а)7+2√10

б)-10+2√21

Answer 2

Ответ:

1) 1. 184

  2. 29

2) 1. 21+6$sqrt{10}$

  2. -10+2$sqrt{21}$

Объяснение:

1) 1. =$3^{2}$- 2*3*5*$sqrt{7}$+$(5sqrt{7}) ^{2}$ + 30

  2. =$3^{2}$ + 2*3*2*$sqrt{5}$+$(2sqrt{5}) ^{2}$ - 12

2)  1. $frac{sqrt{45} +sqrt{18} }{sqrt{5} -sqrt{2} } = frac{sqrt{9*5} +sqrt{9*2} }{sqrt{5} -sqrt{2} } = frac{3*(sqrt{5}+sqrt{2} )}{sqrt{5}-sqrt{2}} = frac{3*(sqrt{5}+sqrt{2} )*(sqrt{5}+sqrt{2} )}{(sqrt{5}-sqrt{2})*(sqrt{5}+sqrt{2})} = frac{3*(sqrt{5}+sqrt{2} )^{2} }{(sqrt{5}) ^{2}-(sqrt{2})^{2} } = frac{3*(5+2sqrt{5}sqrt{2}+2)}{5-4} = frac{3*(7+2sqrt{10}) }{1} = 21+6sqrt{10}$2. $frac{sqrt{48} -sqrt{112} }{sqrt{3} +sqrt{7} } = frac{sqrt{16*3} -sqrt{16*7} }{sqrt{3} +sqrt{7} } = frac{4*(sqrt{3}-sqrt{7} )}{sqrt{3}+sqrt{7}} = frac{4*(sqrt{3}-sqrt{7} )*(sqrt{3}-sqrt{7} )}{(sqrt{3}+sqrt{7})*(sqrt{3}-sqrt{7})} = frac{4*(sqrt{3}-sqrt{7} )^{2} }{(sqrt{3}) ^{2}-(sqrt{7})^{2} } = frac{4*(3-2sqrt{3}sqrt{7}+7)}{3-7} = frac{4*(10-2sqrt{21}) }{-4} = -10+2sqrt{21}$