若7-5x与3(x-1)互为相反数,则x=____

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若7-5x与3(x-1)互为相反数,则x=____若7-5x与3(x-1)互为相反数,则x=____若7-5x与3(x-1)互为相反数,则x=____7-5x=-3(x-1)7-5x=-3x+3-5x

若7-5x与3(x-1)互为相反数,则x=____
若7-5x与3(x-1)互为相反数,则x=____

若7-5x与3(x-1)互为相反数,则x=____
7-5x=-3(x-1)
7-5x=-3x+3
-5x+3x=3-7
-2x=-4
x=-4÷(-2)
x=2

∵7-5x与3(x-1)互为相反数
∴7-5x+3(x-1)=0
-5x+3x-3+7=0
-2x+4=0
-2x=-4
x=2

2

互为相反数,二者和为零
所以 7-5x+3(x-1)=0
解得x=2

x=2

2