-2/3х+2,1=1/4х-1,2 ; 8(-у-2)=-5у-(6-9у) ; -b-(b/4+3/8)=1/2+(-3b/8-0,5)

- 2/3 х+2,1=1/4 х-1,21/4 х+2/3 х=2,1+1,23/12 х+8/12 х=3,311/12 х= 33/10х=33/10 :11/12х=33/10 * 12/11х=18/5=3,68(-у-2)= - 5у-(6-9у)-8у - 16= -5у-6+9у-8у-18=4у-64у+8у=6-1812у = -12у= - 1-b-(b/4 +3/8)=1/2+(-3b/8 -0,5)-b - b/4 - 3/8=1/2 - 3b/8 - 0,5-8b - 2b - 3=4 - 3b-410b-3b= -37b=-3b= -3/7