<span>4x^2y=3
x</span>²y=3/4
6x²y=6*3/4=4,5
4x^4y²=4(x²y)²=4*9/16=9/4=2,25
28.
1) a(b-2)/5(b-2)=a/5( b-2 сокращаем сверху и снизу)
2)3(x+4)/c(x+4)=3/c
3)ab(y+3)/a^2b(y+3)=ab/a^2b=1/a
4)15a(a-b)/20b(a-b)=15a/20b=3a/ 4b
29.
1)3a+12b/6ab=3(a+4b)/6ab=a+4b/ 2ab
3)2a-4/3(a-2)=2(a-2)/3(a-2)=2/3
5)a-3b/a^2-3ab=a-3b/a(a-3b)=1/ a
2)15b-20c/10b=5(3b-4c)/10b=3b-4c/ 2b
4)5x(y+2)/6y+12=5x(y+2)/6(y+2)=5x/ 6
6)3x^2+15xy/x+5y=3x(x+5y)/x+5y=3x
30.
1)y^2-16/3y+12=(y-4)(y+4)/3(y+4)=y-4/ 3
2)5x-15y/x^2-9y^2=5(x-3y)/(x-3y)(x+3y)=5/ x+3y
3)(c+2)^2/7c^2+14c=(c+2)^2/7c(c+2)=c+2/ 7c
4)6cd-18c/(d-3)^2=6c(d-3)/(d-3)^2=6c/ d-3
5)a^2+10a+25/a^2-25=(a+5)^2/(a-5)(a+5)==a+5/ a-5
6)y^2-9/y^2-6y+9=(y-3)(y+3)/(y-3)^2=y+3/ y-3
(/-дробь)
![\frac{18x+36}{4x^{2}-64}=\frac{18(x+2)}{4(x^{2}-16)}](https://tex.z-dn.net/?f=%5Cfrac%7B18x%2B36%7D%7B4x%5E%7B2%7D-64%7D%3D%5Cfrac%7B18%28x%2B2%29%7D%7B4%28x%5E%7B2%7D-16%29%7D)
Теперь решим систему, числитель равен нулю, знаменатель не равен
![\left \{ {{18(x+2)=0} \atop {4(x^{2}-16)\neq 0}} \right.](https://tex.z-dn.net/?f=%5Cleft%20%5C%7B%20%7B%7B18%28x%2B2%29%3D0%7D%20%5Catop%20%7B4%28x%5E%7B2%7D-16%29%5Cneq%200%7D%7D%20%5Cright.)
![18(x+2)=0\\x+2=0\\x=-2](https://tex.z-dn.net/?f=18%28x%2B2%29%3D0%5C%5Cx%2B2%3D0%5C%5Cx%3D-2)
![4(x^{2}-16)\neq 0\\x^{2}-16\neq 0\\(x-4)(x+4)\neq 0\\\\x\neq 4\\x\neq -4](https://tex.z-dn.net/?f=4%28x%5E%7B2%7D-16%29%5Cneq%200%5C%5Cx%5E%7B2%7D-16%5Cneq%200%5C%5C%28x-4%29%28x%2B4%29%5Cneq%200%5C%5C%5C%5Cx%5Cneq%204%5C%5Cx%5Cneq%20-4)
Получаем точки -4 -2 4
Область определения или D(f)=(-∞;-4)∪(-4;2]∪[2;4)∪(4;+∞)
((х-10)² -11)*((х-10)²+11)=0
(х-10)² -11)=0
или
(х-10)² +11) =0
_________________________________________________
(х-10)² -11)=0 (х-10)² +11)=0
х²-20х+100-11=0 х²-20х+100+11=0
х²-20х+99=0 х²-20х+111=0
D=400-396=4 √D=2 D=400-444=-44 нет решений
x₁=(20+2)/2=11
x₂=(20-2)/2=9
Ответ: х=11; х=9