1) -2.4-x=5.43 --> x=-7.83; x+(-2.6)=5.82 --> x=8.42;
x*(-3.45)=5.865 --> x=-1.7; y:2.34=-6.1 --> x=-14.274
2) a) ...=15/3*(2.8-1.6+7.8)=5/3*9=15
б) ...=-1*17/3*(13/17)=1
3) m=-1.3
m²-1.3=-1.3²-1.3=1.69-1.3=0.39
4) (-x+3)*(x+4)=0
-x²-4x+3x+12=0
x²+x-12=0
x₁=-4 x₂=3
|x-2|=6
x-2=6 --> x=8
x-2=-6 --> x=-4