Question

a) x+ 3/4 =1

b) 1/2. x + 5 = -1

c) 3/4 : (2/3.x +-1/5)=6

d) -5/6 . 120/25<x<-7/15 . 9/14  với x thuộc z

Answer 1

a,1/4

b,8

Answer 2

a, 1/4
b,8

Answer 3

a) x=1/4

b) -12

c) 50

d)Vậy x e thuộc {-3, -2, -1}

Answer 4

a) x = 1 - 3/4

    x = 1/4

vậy x =...

b) 1/2.x = (-1) - 5 

    1/2.x = -6

          x = (-6) :1/2

          x = -12

vậy x=...

 

Answer 5

a) \(x+\dfrac{3}{4}=1\)

    \(x=1-\dfrac{3}{4}\)

   \(x=\dfrac{1}{4}\)

b) \(\dfrac{1}{2}\cdot x+5=-1\)

    \(\dfrac{1}{2}\cdot x=\left(-1\right)-5\)

     \(\dfrac{1}{2}\cdot x=-6\)

          \(x=\left(-6\right)\div\dfrac{1}{2}\)

          \(x=-12\)

c) \(\dfrac{3}{4}\div\left(\dfrac{2}{3}\cdot x+\dfrac{-1}{5}\right)=6\)

            \(\left(\dfrac{2}{3}\cdot x+\dfrac{-1}{5}\right)=\dfrac{3}{4}\div6\)

             \(\dfrac{2}{3}\cdot x+\dfrac{-1}{5}=\dfrac{1}{8}\)

             \(\dfrac{2}{3}\cdot x=\dfrac{1}{8}-\dfrac{-1}{5}\)

             \(\dfrac{2}{3}\cdot x=\dfrac{13}{40}\)

                  \(x=\dfrac{13}{40}\div\dfrac{2}{3}\)

                  \(x=\dfrac{39}{80}\)

d) \(\dfrac{-5}{6}\cdot\dfrac{120}{25}< x< \dfrac{-7}{15}\cdot\dfrac{9}{14}\)

   \(\dfrac{-15}{2}< x< \dfrac{-3}{10}\)

   \(\dfrac{-75}{10}< x< \dfrac{-3}{10}\)

Mà x \(\in\) Z

\(\Rightarrow\) \(x=\){\(\dfrac{-74}{10};\dfrac{-73}{10};\dfrac{-72}{10};\dfrac{-71}{10};\dfrac{-70}{10};...;\dfrac{-5}{10};\dfrac{-4}{10}\)}