1) x-16<span><0
x</span><span><16
2) 28x+4</span><span>>0
28x</span><span>>-4
x</span><span>>-1/7
3) 31x+63</span><span>>36x+23
31x-36x</span><span>>23-63
-5x</span><span>>-40
x</span><span>>8</span>
3sin^2x - 4sinxcosx + 5cos^2x = 2*1
<span>3sin^2x - 4sinxcosx + 5cos^2x = 2*(sin^2x+cos^2x)
</span><span>3sin^2x - 4sinxcosx + 5cos^2x = 2sin^2x + 2cos^2x
</span>3sin^2x - 2sin^2x - 4sinx*cosx + 5cos^2x - 2cos^2x = 0
sin^2x - 4sinx*cosx + 3cos^2x = 0 // : cos^2x ≠ 0
tg^2x - 4tgx + 3 = 0
(tgx - 3) (tgx - 1) = 0
tgx = 3
x = arctg(3) + pik, k ∈Z
tgx = 1
x = pi/4 + pik, k ∈Z
1)
0,5(x-6)^2+2x(8-x/4)=2
0,5(x^2-12x+36)+16x-x^2/2=2
0,5x^2-6x+18+16x-x^2/2=2
0,5x^2+10x+18-0,5x^2=2
10x=2-18
10x=-16
x=-16/10=-1,6
2)
y+(5y+2)^2=25(2+y^2)
y+25y^2+20y+4=50+25y^2
21y+4=50
21y=46
y=46/21=2 4/21