2,5(2x+3y-5)=5x+7,5y-12,5
3(8m-7-6p)=24m-21-18p
5(9a-4b+2c)=45a-20b+10c
2a(3b-8c-5д)=6ab-16ac-10aд
2a+2b=2(a+b)=2(-4.1+4.05)=-2*0.05=-0.1
5[-5y=5(x-y)=5(-6.2-(-6.02))=5(-6.2+6.02)=-5*0.18=-0.9
2 1/3b-4+1 2/3b=4b-4=4*3/4-4=3-4=-1
5)=-tgα/-cosα* -cosα/-ctgα=tgα/ctgα=tg²α
6)(4cos20+12cos(360+180-20))/-2cos(360-20)=4cos20-12cos20)/-2cos20=
=-8cos20/-2cos20=4
7) =(6ctg(2π+7π/18)-4tgπ/9)/4ctg(11π/18-3ctg(2π+11π/18))=(6ctg(π/2-π/9)-4tgπ/9)/
/(4ctg11π/18-3ctg11π/18)=6tgπ/9-4tgπ/9)/(4ctg11π/18-3ctg11π/18=2tgπ/9)/ctg11π/18=
=2tgπ/9)/ctg(π/2+π/9)=2tgπ/9)/-tgπ/9=-2
ох замучил