a,-14-7+x=-12 b,x+(-15)-(-6)=11 c,x-[18+(-7)]=15 d,-84-(-18-6)=x+(-20)
-21+x=-12 x+(-15)+6=11 x-11=15 -84-(-12)+x+(-20)
x=-12-(-21) x+(-9)=11 x=15+11 x+(-20)=-84+12
x=-12+21 x=11-(-9) x=26 x+(-20)=-62
x=9 x=11+9 x=-62-(-20)
x=20 x=-62+20
x=-42
a) -14 - 7 + x = -12
-21 + x = -12
x = 9
b) x + (-15) - (-6) = 11
x - 15 + 6 = 11
x - 9 = 11
x = 20
c) x - [ 18 + (-7) ] = 15
x - ( 18 - 7 ) = 15
x - 18 + 7 = 15
x - 11 = 15
x = 26
d) -84 - ( -18 - 6 ) = x + (-20)
-84 +18 + 6 = x - 20
-60 = x - 20
x = -40