10sin²x-6sinxcosx-8sin²x-8cos²x=0
2sin²x-6sinxcosx-8cos²x=0/2cos²x≠0
tg²x-3tgx-4=0
tgx=a
a²-3a-4=0
a1+a2=3 U a1*a2=-4
a1=-1⇒tgx=-1⇒x=-π/4+πn
a2=4⇒tgx=4⇒x=arctg4+πn
V30+V35/V12+V14=V5*V6+V5*V7/V2*V6+V2*V7=V5(V6+V7)/V2(V6+V7)=
=V5/V2 Vx+Vy/x-y=Vx+Vy/Vx^2-Vy^2=Vx+Vy/(Vx-Vy)(Vx+Vy)=1/Vx-Vy
14-x-(x+4)=x (x-5)
14-x-x-4=x^2-5x
-x^2+3x+10=0
x^2-3x-10=0
x1+x2=3 x1 =-2
x1×x2=- 10 x2= 5
Ответ: -2 и 5
40(х+4) - 40х
------------------------=20
х(х+4)
40х-160-40х ОДЗ не =0,х не =0 х+4 не=-4
------------------=20
х(х+4)
20х(х+4)=160 /:20
х(х+4)=8
х^2+4=8
X^2=4
X=2