3x^5- 6x³- 21x²- 3x^5+6x³+20x²+x² - 18x - 54=0
- 18x-54=0
- 18x=54
x= - 54:18
x= - 3
1/3^х+5 = 3³ 3^-(х+5)=3³ -х-5=3 -х=3+5 -х=8 х=-8
1
[cos(π-b)-3sin(-3π/2+b)]/cos(b-3π)=[-cosb+sin(3π/2-b)]/cos(b-π)=
=[-cosb-cosb)/(-cosb)=-2cosb/(-cosb)=-2
3
24√2cos1035=24√2cos(720+315)=24√2cos315=24√2cos(360-45)=
=24√2cos45=24√2*1/√2=24
6
11sin49/sin311=11sin49/sin(360-49)=11sin49/(-sin49)=-11
1) ax^2-(a+c)x+c = ax^2 - ax - cx +c = x(ax - c) - (ax - c) = (x - 1)(ax - c).
2) 56y^2+ay-a^2 = 49y^2 + 7y^2+ay - a^2 = (7y - a)(7y + a) + y(7y + a) = (8y - a)(7y + a).