Question

[DEAR KEV Invincible]

tìm x thuộc Z:
-(-432-3x)+(-432-4x+21)=-2345

12x-(-3546-3x)=(2x-234)-(-678-2x)

Answer 1

[Jane The Killer]

a/\(-\left(-432-3x\right)+\left(-432-4x+21\right)=-2345\)

\(\Leftrightarrow+432+3x-432-4x+21=-2345\)\(\Leftrightarrow\left[432+\left(-432\right)\right]+\left[\left(-4x\right)+3x\right]+21=-2345\)

\(\Leftrightarrow0+-1x+21=-2345\)\(\Leftrightarrow-1x=-2345-21=-2366\)

\(\Rightarrow x=\left(-2366\right):\left(-1\right)=2366\)

b/\(12x-\left(-3546-3x\right)=\left(2x-234\right)-\left(-678-2x\right)\)

\(\Leftrightarrow12x+3546+3x=2x-234+678+2x\)

\(\Leftrightarrow15x+3546=\left(2x+2x\right)+\left[\left(-234\right)+678\right]\)

\(\Leftrightarrow15x+3546=4x+444\)

\(\Leftrightarrow15x+3546-4x-444=0\)

\(\Leftrightarrow\left(15x-4x\right)+\left(3546-444\right)=0\)

\(\Leftrightarrow11x+3102=0\)

\(\Leftrightarrow11x=0-3102=-3102\)

\(\Rightarrow x=\left(-3102\right):11=-282\)