№1.1)
![\frac{25}{45}= \frac{5}{9} \frac{25}{45}= \frac{5}{9}](https://tex.z-dn.net/?f=\frac{25}{45}= \frac{5}{9} )
;2)
![\frac{63}{49}=\frac{9}{7}=1\frac{2}{7} \frac{63}{49}=\frac{9}{7}=1\frac{2}{7}](https://tex.z-dn.net/?f=\frac{63}{49}=\frac{9}{7}=1\frac{2}{7} )
;
3)
![-\frac{77}{99}=-\frac{7}{9} -\frac{77}{99}=-\frac{7}{9}](https://tex.z-dn.net/?f=-\frac{77}{99}=-\frac{7}{9})
;
4)
![-\frac{39}{52}=\frac{3}{4} -\frac{39}{52}=\frac{3}{4}](https://tex.z-dn.net/?f=-\frac{39}{52}=\frac{3}{4})
.№2.1)
![\frac{9}{11} \frac{9}{11}](https://tex.z-dn.net/?f= \frac{9}{11} )
=
![\frac{36}{x} \frac{36}{x}](https://tex.z-dn.net/?f= \frac{36}{x} )
, x=
![\frac{36*11}{9} \frac{36*11}{9}](https://tex.z-dn.net/?f= \frac{36*11}{9} )
=44,Ответ: 44;2)
![\frac{7}{4} \frac{7}{4}](https://tex.z-dn.net/?f= \frac{7}{4} )
=
![\frac{x}{60} \frac{x}{60}](https://tex.z-dn.net/?f= \frac{x}{60} )
,x=
![\frac{60*7}{4} \frac{60*7}{4}](https://tex.z-dn.net/?f= \frac{60*7}{4} )
=105,Ответ: 105.№3. 1) 5a²-20a=5a(a-4),2) 12a²b+18ab²=6ab(2a+3b),3) 4x²-25y²=(2x-5y)(2x+5y),4) 7x²-28=7(x²-4)=7(x-2)(x+2).№4.1) (x+7)(2x-5)=0,2x²-5x+14x-35=0,2x²+9x-35=0,D=b²-4ac=81-4*2*(-35)=81+280=361=19²,
![x_{1}=\frac{-b + \sqrt{D} }{2a}=\frac{-9+19}{2*2}=2,5,
x_{2}=\frac{-b - \sqrt{D} }{2a}\frac{-9-19}{2*2}=7 x_{1}=\frac{-b + \sqrt{D} }{2a}=\frac{-9+19}{2*2}=2,5,
x_{2}=\frac{-b - \sqrt{D} }{2a}\frac{-9-19}{2*2}=7](https://tex.z-dn.net/?f=x_{1}=\frac{-b + \sqrt{D} }{2a}=\frac{-9+19}{2*2}=2,5,
x_{2}=\frac{-b - \sqrt{D} }{2a}\frac{-9-19}{2*2}=7)
Ответ: 2,5 ; 7.2) x(2x-3)(x-6)=0,x(2x²-12x-3x+18)=0,x(2x²-15x+18)=0, x=0 и 2x²-15x+18=0,Аналогично пункту 1):2x²-15x+18=0,D=225-4*2*18=9²;
![x_{2} x_{2}](https://tex.z-dn.net/?f= x_{2} )
= 6,
![x_{3} x_{3}](https://tex.z-dn.net/?f= x_{3} )
= 1,5,Ответ: 0; 6; 1,5.3) 9x²-1=0,9x²=1,x²=
![\frac{1}{9} \frac{1}{9}](https://tex.z-dn.net/?f= \frac{1}{9} )
,x=
![\sqrt{ \frac{1}{9} } = \frac{1}{3} \sqrt{ \frac{1}{9} } = \frac{1}{3}](https://tex.z-dn.net/?f= \sqrt{ \frac{1}{9} } = \frac{1}{3} )
,Ответ:
![\frac{1}{3} \frac{1}{3}](https://tex.z-dn.net/?f= \frac{1}{3} )
.4)x³-16x=0,x(x²-16)=0,x=0 и x²=16,x=0 и x=
![\sqrt{16} =4 \sqrt{16} =4](https://tex.z-dn.net/?f= \sqrt{16} =4)
,Ответ: 0 ; 4.№5. 1) |x|=10, x=+-10, Ответ: 10; -10;2)|x|=0,7, x=+-0,7, Ответ: 0,7; -0,7.№6.1) a>0, |a|=a,2) a=0, |0|=0,3) a<0, |a|=a.