Решение:
(у-476)-1056=1549
у=1549+1056+476
у=3081
4 т 3 ц × 4 = 43 × 4 = 172
(2cos54+3cos36-2cos144)/(sin70sin74-sin20sin16)=
=(2cos(90-36)+3cos36-2cos(180-36))/(sin(90-20)sin(90-16)-sin20sin16)=
=(2sin36+3cos36+2cos36)/(cos20cos16-sin20sin16)=(2sin36+5cos36)/cos(20+16)=
=(2sin36+5cos36)/cos36=2tg36+5