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1)
![frac{ x^{2} }{ x^{2} -9} = frac{12-x}{ x^{2} -9} \ \
frac{ x^{2} }{ x^{2} -9} -frac{12+x}{ x^{2} -9} = 0 \ \
frac{ x^{2} -12+x}{ x^{2} -9}=0 \ \
frac{ x^{2} +x-12}{ x^{2} -9}=0 \ \
frac{ x^{2} +x-12}{ x^{2} -9}=0 \ \
frac{(x+4)(x-3)}{(x-3)(x+3)} =0 \ \
frac{x+4}{x+3}=0 \ \
left { {{x=-4} atop {x neq -3 (3)}} right.](https://tex.z-dn.net/?f=+frac%7B+x%5E%7B2%7D+%7D%7B+x%5E%7B2%7D+-9%7D+%3D++frac%7B12-x%7D%7B+x%5E%7B2%7D+-9%7D++%5C++%5C+%0A+frac%7B+x%5E%7B2%7D+%7D%7B+x%5E%7B2%7D+-9%7D+-frac%7B12%2Bx%7D%7B+x%5E%7B2%7D+-9%7D+%3D+0+%5C++%5C+%0A+frac%7B+x%5E%7B2%7D+-12%2Bx%7D%7B+x%5E%7B2%7D+-9%7D%3D0+%5C++%5C+%0Afrac%7B+x%5E%7B2%7D+%2Bx-12%7D%7B+x%5E%7B2%7D+-9%7D%3D0+%5C++%5C+%0Afrac%7B+x%5E%7B2%7D+%2Bx-12%7D%7B+x%5E%7B2%7D+-9%7D%3D0+%5C++%5C+%0A+frac%7B%28x%2B4%29%28x-3%29%7D%7B%28x-3%29%28x%2B3%29%7D+%3D0+%5C++%5C+%0A+frac%7Bx%2B4%7D%7Bx%2B3%7D%3D0+%5C++%5C+%0A+left+%7B+%7B%7Bx%3D-4%7D+atop+%7Bx+neq+-3+%283%29%7D%7D+right.++%0A%0A+ "frac{ x^{2} }{ x^{2} -9} = frac{12-x}{ x^{2} -9} \ \
frac{ x^{2} }{ x^{2} -9} -frac{12+x}{ x^{2} -9} = 0 \ \
frac{ x^{2} -12+x}{ x^{2} -9}=0 \ \
frac{ x^{2} +x-12}{ x^{2} -9}=0 \ \
frac{ x^{2} +x-12}{ x^{2} -9}=0 \ \
frac{(x+4)(x-3)}{(x-3)(x+3)} =0 \ \
frac{x+4}{x+3}=0 \ \
left { {{x=-4} atop {x neq -3 (3)}} right.")
2)
![frac{6}{x-2} + frac{5}{x} =3 \ \
xneq 2 , x neq 0 \ \
frac{6x+5(x-2)-3x(x-2)}{x(x-2)} =0 \ \
frac{6x+5x-10-3 x^{2} +6x}{x(x-2)}=0 \ \
frac{17x-10-3 x^{2} }{x(x-2)}=0 \ \
17x-10-3 x^{2}=0 \ \
x=5 \ \
x= frac{2}{3}](https://tex.z-dn.net/?f=+frac%7B6%7D%7Bx-2%7D+%2B++frac%7B5%7D%7Bx%7D+%3D3+%5C++%5C+%0A+xneq+2+%2C+x+neq+0+%5C++%5C+%0A+frac%7B6x%2B5%28x-2%29-3x%28x-2%29%7D%7Bx%28x-2%29%7D+%3D0+++%5C++%5C+%0A+frac%7B6x%2B5x-10-3+x%5E%7B2%7D+%2B6x%7D%7Bx%28x-2%29%7D%3D0+%5C++%5C+%0A+frac%7B17x-10-3+x%5E%7B2%7D+%7D%7Bx%28x-2%29%7D%3D0+%5C++%5C+%0A17x-10-3+x%5E%7B2%7D%3D0+%5C++%5C+%0Ax%3D5+%5C++%5C+%0Ax%3D+frac%7B2%7D%7B3%7D+%0A++%0A+ "frac{6}{x-2} + frac{5}{x} =3 \ \
xneq 2 , x neq 0 \ \
frac{6x+5(x-2)-3x(x-2)}{x(x-2)} =0 \ \
frac{6x+5x-10-3 x^{2} +6x}{x(x-2)}=0 \ \
frac{17x-10-3 x^{2} }{x(x-2)}=0 \ \
17x-10-3 x^{2}=0 \ \
x=5 \ \
x= frac{2}{3}")
(3)
Я делал по таблице, фото прикреплю:
![frac{50}{18+x} + frac{8}{18-x} =3 \ \
x neq -18 \ x neq 18 \ \
frac{50(18-x)+8(18+x)-3(18+x)(18-x)}{(18+x)(18-x)}=0 \ \
frac{900-50x+144+8x-3( 18^{2} - x^{2} )}{(18+x)(18-x)} =0 \ \
frac{72-42x+3 x^{2} }{(18+x)(18-x)}=0 \ \
72-42x+3 x^{2} =0 \ \
x=12 ! \ \
x=2](https://tex.z-dn.net/?f=+frac%7B50%7D%7B18%2Bx%7D+%2B+frac%7B8%7D%7B18-x%7D+%3D3+%5C++%5C+%0Ax+neq+-18+%5C+x+neq+18+%5C++%5C+%0A+frac%7B50%2818-x%29%2B8%2818%2Bx%29-3%2818%2Bx%29%2818-x%29%7D%7B%2818%2Bx%29%2818-x%29%7D%3D0+%5C++%5C++%0A+frac%7B900-50x%2B144%2B8x-3%28+18%5E%7B2%7D+-+x%5E%7B2%7D+%29%7D%7B%2818%2Bx%29%2818-x%29%7D+%3D0+%5C++%5C+%0A+frac%7B72-42x%2B3+x%5E%7B2%7D+%7D%7B%2818%2Bx%29%2818-x%29%7D%3D0+%5C++%5C+%0A72-42x%2B3+x%5E%7B2%7D+%3D0+%5C++%5C+%0Ax%3D12+%21+%5C++%5C+%0Ax%3D2+%0A+ "frac{50}{18+x} + frac{8}{18-x} =3 \ \
x neq -18 \ x neq 18 \ \
frac{50(18-x)+8(18+x)-3(18+x)(18-x)}{(18+x)(18-x)}=0 \ \
frac{900-50x+144+8x-3( 18^{2} - x^{2} )}{(18+x)(18-x)} =0 \ \
frac{72-42x+3 x^{2} }{(18+x)(18-x)}=0 \ \
72-42x+3 x^{2} =0 \ \
x=12 ! \ \
x=2")
12 очень большая скорость, поэтому скорость течения - 2км/час.
(3) а-очень плохо видно
б)
(5/6+1*1/10)*24
(5/6+11/10)*24=(25/30+33/30)*24=58/30*24=29/15*24=(29*24)/15=232/5=46 2/5=46,4
2)
(3)
Я делал по таблице, фото прикреплю:
12 очень большая скорость, поэтому скорость течения - 2км/час.
(3) а-очень плохо видно
б)
(5/6+1*1/10)*24
(5/6+11/10)*24=(25/30+33/30)*24=58/30*24=29/15*24=(29*24)/15=232/5=46 2/5=46,4
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