x+30=60-40
x+30=20
x=20-30
x=-10
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x + 30 = 60 - 40
x + 30 = 20
x = 20 - ( -30 )
x = - 10
x + 30 = 60 - 40
=> x + 30 = 20
=> x = 20 - 30
=> x = -10
x + 30 = 60 - 40
x + 30 = 20
x = 20 - 30
x = -10
x+30=60—40
x+30=20
x=20—30
x=—10