Răspuns :


2X+23= 91    2X=91-23   2X=68  X=34

327-3X=15+48      327-15-48=3X      264=3X  X=264÷3=88

15+X+2+21=47   X=47-15-2-21    X=8

32+2X-5=77     2X=77-32+5   2X=40    X=20

X=638-542+117     X=213

19+X<43     X<43-19     X<24   X∈ { 0,1,2,3,4,5,......23}

28-X≥11      28-11≥X    X≤17    X∈ {0,1,2,3,........17}

X+38-18<83    X< 83-38 +18     X< 63       X∈ {0,1,2,3,......62}