19a -7b+12
<u>5a-8b+2</u> =3
8a-5b+2
5a-8b+2=3(8a-5b+2)
5a-8b+2=24a-15b+6
5a-24a-8b+15b+2-6=0
-19a+7b-4=0
19a-7b+4=0
19a-7b+12=19a-7b+4+8=0+8=8
Ответ: 8
2sin3x=-1
sin3x=-1/2
3x=7π/6+2πn U 3x=11π/6+2πn
x=7π/18+2πn/3 U x=11π/18+2ππn/3
x={-31π/36;-3π/4;-π/4;-π/12;15π/36;7π/12;35π/36;5π/4}