210:х=-3; 210+х=-65; 210*х=-10; 210+х=130; 210+х=-65; 210-х=350.
1) 210:х=-3; х=210:(-3)=-70 2)210+х=-65; х=-65-210=-275 3)210*х=-10 х=-10:210=1/21 4)210+х=130; х=130-210=-80 5) 210-х=350; -х=350-210=140; -х=140; х=-140