(√18 +√3)*√2 -0.5√2 =(√18*√2) +(√3*√2) -0.5√2 =√(18*2) +√(3*2) -0.5√2 =√36 +√6 -0.5√2 =6 +√6 -0.5√2
Cos²x = Sin²x
Cos²x - Sin²x = 0
Cos2x = 0
2x = П/2 + Пn, n э z
x = П/4 + Пn/2, n э z
X^2 - ( x + 3 )( x - 3 ) = 3x
x^2 - ( x^2 - 9 ) = 3x
x^2 - x^2 + 9 = 3х
х = 9 : 3
х = 3
(20⁻⁴ *15⁻³)/30⁻⁷=((4*5)⁻⁴ *(3*5)⁻³)/(2*3*5)⁻⁷=((2²)⁻⁴ *5⁻⁴ *3⁻³ *5⁻³)/(2⁻⁷ *3⁻⁷ *5⁻⁷)=(2⁻⁸ *3⁻³ *5⁻⁷)/(2⁻⁷ *3⁻⁷ *5⁻⁷)=2⁻⁸⁻(⁻⁷) *3⁻³⁻(⁻⁷)*5⁻⁷⁻(⁻⁷)=2⁻¹ *3⁴ *1=(1/2)*81=81/2=40,5