4
[2(a-c)+x(a-c)]/(x²-4)=(a-c)(2+x)/(x-2)(x+2)=(a-c)/(x-2
x=1,9 c=5,3 a=6,7
(6,7-5,3)/(1,9-2)=1,4/(-0,1)=-14
5
4(x+2)²-2(x²-4)-(x-2)²=x²
4x²+16x+16-2x²+8-x²+4x-4-x²=0
20x=-20
x=-1
6
a)(x+y)/x*x²/a(x+y)=x/a
б)9x^10/y^12
в)(a-b)(a+b)/b*b/a(a+b)=(a-b)/a
г)3(a-c)/a*1/(a-c)(a+c)=3/a(a+c)
7
1)1/(x-y)-1/(x+y)=(x+y-x+y)/(x²-y²)=2y/(x²-y²)
2)2y/(x²-y²)*(x²-y²)/y²=2/y
8
(a+3)(a-3)/2(a+4)*4(a+4)/(a+3)²=2(a-3)/(a+3)
a=1,8
2(1,8-3)/(1,8+3)=-2*1,2/4,8=-2/4=-0,5
9
1)1/(x+y)*2(x+y)/xy=2/xy
2)1/x²+1/y²+2/xy=(y²+x²+2xy)/x²y²=(x+y)²/x²y²
3)(x+y)²/x²y²*x²y²/(x-y)(x+y)=(x+y)/(x-y)