(630-х)+210=500 ; (х+190) -370=330

Question

(630-х)+210=500 ; (х+190) -370=330

Answer 1

(630-х)+210=500
630-х+210=500
840-х=500
-х=500-840
-х=-340
х=340

(х+190)-370=330
х+190-370=330
х=330-190+370
х=510