1)x>0
x=-x
2x=0
x=0
2)x<0
-x=-x
0=0
от (- бексонечность;0]
Sin⁴x-cos⁴x=(sin²x)²-(cos²x)²=(sin²x+cos²x)(sin²x-cos²x)=
=1*(sin²x-cos²x)=-(cos²x-sin²x)= -cos(2x)
А) (m¼ - n½)² - (m¼ + n½)²=m^1/2-2(mn)^1/4+n^1/2+m^1/2+2(mn)^1/4+n^1/2=
=2√m+2√n<span>
б) (m⅓ + 3n½)² + (m⅓ - 3n½)²=
=m^2/3+6m^1/3n^1/2+9n+</span>m^2/3-6m^1/3n^1/2+9n=2∛m²+18n<span>
в) (m½ - 2n¼) (m½ + 2n¼)=m-4</span>√n<span>
г) (m½ - 3n) (m + 3m½n + 9n²)=m^3/2-27n</span>³=√m³-27n³
2x-5y=3
1)4x-10y=6, 2x-5y=3, da
2)4x-10y=3, 2x-5y=1,5, net
3)2x-5y=6 , net
4)5y-2x=-3,2x-5y=3 , da
5)x-2,5y =1,5, 2x-5y=3,da
6)-0,4x-y=0,6, 2x+5y=-3, net