863-(a+219)=196 (901-x)+478=802
863-(a+219)=196 a+219=863-196 a+219=667 a=667-219 a=448 863-(448+219)=196 196=196 (901-x)+478=802 901-x=802-478 901-x=324 x=901-324 x=577 (901-577)+478=802 802=802