1) a2-b2/6a2b2 : a+b/3ab = (a-b)(a+b)/3ab*2ab * 3ab/a+b= a-b/2ab
2) a2b-4b3/3ab2*a2b/a2-2ab = b(a2-4b)/3ab2 * a2b/a(a-2b)= (a-2b)(a+2b)/3a(a-2b)=
a+2b/3a
3) <span>x2-xy/x2+xy × x2y + xy2/xy = x(x-y)/x(x+y) * y= y(x-y)/x+y</span>
1-2sin4x<1-sin²4x
sin²4x-2sin4x<0
sin4x(sin4x-2)<0
1
{sin4x<0⇒π+2πk<4x<2π+2πk⇒π/4+πk/2<x<π/2+πk/2
{sin4x>2 нет решения
2
sin4x>0⇒2πk<4x<π+2πk⇒πk/2<x<π/4+πk/2
{sin4x<2⇒x∈R
x∈(πk/2;π/4+πk/2,k∈z)
-18х:(-2)=9х
2в:5=0,4в
-3,8а*10= - 38а
2а:2а=1
4х:2х=2
-m:10= - m/10
7а:-(1/7)=- 49а
остальное правильно
75²⁰ = (25 * 3)²⁰ =(5² * 3)²⁰ = 5⁴⁰ * 3²⁰
45¹⁰ * 5³⁰ = (5 * 9)¹⁰ * 5³⁰ = 5¹⁰ * (3²)¹⁰ * 5³⁰ = 5⁴⁰ * 3²⁰
5⁴⁰ * 3²⁰ = 5⁴⁰ * 3²⁰ ⇒ 75²⁰ = 45¹⁰ * 5³⁰