1) [tex] \sqrt{8-a}[/tex]
2) [tex](\sqrt{8- 2\sqrt{7}} - \sqrt{8+ 2\sqrt{7}})²[/tex]
3) [tex] \frac{1}{2\sqrt{5-4}} - \frac{1}{4+2\sqrt{5}} [/tex]
2) [tex](\sqrt{8- 2\sqrt{7}} - \sqrt{8+ 2\sqrt{7}})²[/tex]
3) [tex] \frac{1}{2\sqrt{5-4}} - \frac{1}{4+2\sqrt{5}} [/tex]
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task/26048835-------------------
2)
B=√(8 -2√7 ) - √(8 +2√7 ) =√(7 -2√7+1) - √(7 +2√7+1 ) =
( √( (√7)² -2√7+1²) - √( (√7)² +2√7+1²) )=√( √7 -1)² - √( √7 +1)² =
√7 -1 - ( √7 +1) = - 2. ; B²=(-2)²= 4 .
ответ : 4 .
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3)
1/(2√5 - 4) -1/(2√5 +4) =( 2√5 +4 - (2√5 - 4) )/ (2√5 - 4) (2√5 +4) =
( 2√5 +4 - 2√5 + 4) / ( (2√5)² - 4² ) = 8 / (4*5 -16) =8/4 = 2.
ответ : 2 .