4x+2(79-x)=192 3200=450+5X+X (0.5+x)+x=9.8÷2.

问题描述:

4x+2(79-x)=192     
3200=450+5X+X       
(0.5+x)+x=9.8÷2.

(1)4x+2(79-x)=192,
            4x+158-2x=192,
               2x+158=192,
           2x+158-158=192-158,
                2x÷2=34÷2,
                    x=17.
(2)3200=450+5X+X,
     3200=450+6X,
 3200-450=450+6X-450,
  2750÷6=6X÷6,
        X=458

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(3)(0.5+x)+x=9.8÷2,
          0.5+2x=4.9,
      0.5+2x-0.5=4.9-0.5,
           2x÷2=4.4÷2,
               x=2.2.