7
a((y-4)(y+4)/3(y+4)=(y-4)/3
b)(c+2)²/5c(c+2)=(c+2)/5c
c)(x+5)²/(x-5)(x+5)=(x+5)/(x-5)
d)3x(x-3y)/(x-3y)(x+3y)=3x/(x+3y)
8
a)3(a-4b)/6ab=(a-4b)/2ab
b)5(3b-2c)/10b=(3b-2c)/2b
c)2(a+2)/3(a+2)=2/3
d)5x(y+3)/6(y+3)=5x/6
e)10(a-b)/15(b-a)=-2/3
9
a)4a(3a+2b)/b(3a+2b)=4a/b
a=0,5;b=0,2 4*0,5/0,2=2/0,2=10
b)(x-3y)²/2x(x-3y)=(x-3y)/2x
x=1,5;y=-0,5 (1,5+1,5)/3=3/3=1
10
a)3(x+3)≠0
x≠-3
x∈(-∞;-3) U (-3;∞)
b)2(x-2)≠0
x≠2
x∈(-∞;2) U (2;∞)
c)(a-3)(a+3)≠0
a≠3 U a≠-3
a∈(-∞;-3) U (-3;3) U (3;∞)
d)(y-7)(y+7)≠0
y≠7 u y≠-7
y∈(-∞;-7) U (-7;7) U (7;∞)