3 - 4sin²(3x + π/3) = 0
3 = 4sin²(3x + π/3)
sin²(3x + π/3) = 3/4
sin(3x + π/3) = ±√3/2
1) sin(3x + π/3) = √3/2
3x + π/3 = (-1)ⁿπ/3 + πn, n ∈ Z
x = (-1)ⁿπ/9 - π/9 + πn/3, n ∈ Z
2) sin(3x + π/3) = -√3/2
3x + π/3 = (-1)ⁿ+¹π/3 + πn, n ∈ Z
x = (-1)ⁿ+¹π/9 - π/9 + πn/3, n ∈ Z
0,78*3,4/(6-6,7)=0,78*3,4/(-0,7)=-7,8*3,4/7=-26,52/7=-2652/700=-3 138/175.
(a+b)²-(c-d)²+(a+c)²-(b-d)²=(a+b-c-d)(a+b+c+d)+(a-b+c-d)(a+c+b+d)=
=(a+b+c-d)(a+b-c-d+a+c-b-d)=2(a-d)(a+b+c+d)
1) 0.2х+1.1х=1.4-2.7
1.3х=-1.3
х=1.3:1.3
х=-1
2) 5.4+3.6=0.3х+1.5х
9=1.8х
х=9:1.8
х=5
3) 1/8х-1/6х=10-15
-1/24х=-5
х=-5:(-1/24)
х=120