Question

tìm x:

1) \(\frac{x-4}{12}=\frac{x-6}{11}\)

2)\(\frac{3x+2}{-7}=\frac{x-4}{-2}\)

3)\(\frac{1-4x}{5}=\frac{2x-1}{-3}\)

Answer 1

a, \(\frac{x-4}{12}=\frac{x-6}{11}\)

\(\Rightarrow11\left(x-4\right)=12\left(x-6\right)\)

\(\Rightarrow11x-44=12x-72\)

\(\Rightarrow11x-12x=-72+44\)

\(\Rightarrow-x=-28\)

=> x = 28

b, \(\frac{3x+2}{-7}=\frac{x-4}{-2}\)

\(\Rightarrow-2\left(3x+2\right)=-7\left(x-4\right)\)

\(\Rightarrow-6x+\left(-4\right)=-7x-\left(-28\right)\)

\(\Rightarrow-6x+\left(-4\right)=-7x+28\)

\(\Rightarrow-6x+7x=28-\left(-4\right)\)

\(\Rightarrow x=32\)

c, \(\frac{1-4x}{5}=\frac{2x-1}{-3}\)

\(\Rightarrow-3\left(1-4x\right)=5\left(2x-1\right)\)

\(\Rightarrow-3-\left(-12x\right)=10x-5\)

\(\Rightarrow-3+12x=10x-5\)

\(\Rightarrow-3+5=10x-12x\)

\(\Rightarrow2=-2x\)

=> x = 2 : (-2)

=> x = -1

Answer 2

1) X=28

2) X=32

3) X=-1