решите пожалуйста,очень надо.

1) а)(3.6-1.62=1.98)
-2.4-1.98=-4.38
б) 6*8/9 + (-2*8/9 + 3*4/7) = 48/9+(-16/9+12/7)=16/3+ -112+108/63= 16/3+ -4/63= 16/3-4/63=336-4/63=332/63
в) (4/5 + 5/6) + -21/10 - (29/5+ -79/10)= -21/10+ 24+25/30 - (29/5-79/10)=49/30-21/10 - 58-79/10= 49/30 + -21+(-58)+79/10= 49/30
2) а) -(3,2+m)+1.2=-(m+3.2)+1.2=-m-3.2+1.2=-m-2
б) -(-b+1.2)+3.2=3.2+b-1.2=b+2
в)(-k+5.9)+k=k+(-k)+5.9=5.9
г)(-2.8+n)-n=-n+(n-2.8)=-n+n-2.8=-2.8
д)(3.8+x)-(-x+1.2)=(x+3.8)+x-1.2=x+3.8+x-1.2=2x+2.6
е)(4.3-y)-(5.8+y)=-(y+5.8)+(-y+4.3)=-y-5.8+(-y)+4.3=-2y-1.5
3) a) 5.6-(4.5+(-2.4))=-(4.5-2.4)+5.6=5.6-2.1=3.5
б)0.4-(-(-0.3)+1.2)+(-0.3)=0.4-0.3-(0.3+1.2)=-1.5+0.1=-1.4