Х+9=4; 21+х=-7; Х+(-15)=-22
Х=4-9=-5 х=-7-21=-28 х=-22+15=-7
1)x+9=4 x=4-9 x=-5 2)21+x=-7 x=-7-21 x=-28 3)x+(-15)=-22 x=-22+15 x=-7