1)4,7 x5 y5 z * 3/8 x4 y3 z=141/80 x9 y8 z2
2) 5a2 - 2a2 + a2 = 4a2 = 64/49 pri a=4/7
3) 5c2d - 2c2d + c3d + 2c3d = 2d(5c-2c)? 3d(c+2c)= 3c2d + 3c3d = 3c5d
4) ...= -8b5 c2 d - b2 c2 = b2 c2 (-8b3 d - 1)
Sin²x+cos²x-6сos²x-4sinxcosx-cos²x+sin²x=0/cos²x
2tg²x-4tgx-6=0
tg²x-2tgx-3=0
tgx=a
a²-2a-3=0
a1+a2=2 U a1*a2=-3
a1=-1⇒tgx=-1⇒x=-π/4+πn,n∈z
a2=3⇒tgx=3⇒x=arctg3+πk,k∈z
A= u-u0/t
at=u-u0
t=(u-u0)/a
-18=k*3 , k=-18/3 , k=-6 .