№2
в)x^2 +64=0
x^2 = - 64
/x/=√64
x= 8 x= - 8
Ответ: 8 ; - 8.
г) 3x^2 - 15=0
3x^2 = 15
x^2 = 5
/x/ = √5
x=√5 x= - √5
Ответ: √5 ; -√5
№3
x^2-3x-10=0
D=b^2 - 4ac = ( -3)^2 - 4 * 1 * ( - 10) = 9+40=49
√D=7
x1=3+7 / 2 = 5
x2= 3 - 7 / 2 = ⇒ - 2 - Является .
Ответ: 5; - 2
№4
![( \sqrt{5}- \sqrt{2})^2=( \sqrt{6})^2-2 \sqrt{5}* \sqrt{2}+( \sqrt{2})^2=5- 2\sqrt{10}+2=7+2 \sqrt{10}](https://tex.z-dn.net/?f=%28+%5Csqrt%7B5%7D-+%5Csqrt%7B2%7D%29%5E2%3D%28+%5Csqrt%7B6%7D%29%5E2-2+%5Csqrt%7B5%7D%2A+%5Csqrt%7B2%7D%2B%28+%5Csqrt%7B2%7D%29%5E2%3D5-+2%5Csqrt%7B10%7D%2B2%3D7%2B2+%5Csqrt%7B10%7D+)
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![(4- \sqrt{10})(4+ \sqrt{10})=(4^2-( \sqrt{10})^2)=16-10=6](https://tex.z-dn.net/?f=%284-+%5Csqrt%7B10%7D%29%284%2B+%5Csqrt%7B10%7D%29%3D%284%5E2-%28+%5Csqrt%7B10%7D%29%5E2%29%3D16-10%3D6)
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4х^2+24х+36/х -3 : х/3х -9 -3/х^2 +зх+х^2 +9/27 -3х^2 |*27х^2
108х^4 +648х^3 +972х -81х^2 : 9х-243х^2-81+81х^3
0,5 дм=5см, 100 мм=10 см
5*2=10 пл. наименьш. грани
5*10=50 пл. наиб. грани
10+50=60
<span>0,3+0,2х≥0,6х-4,1
0.3+4.1>=0.6x-0.2x
4.4>=0.4x
x<=11</span>