Question

Tìm số nguyên x\(\varepsilon\)Z:

a, 7x = -14

b,6x - (-5) = 17

c,(x + 2) . (x - 9) = 0

Answer 1

a) 7x = -14

x= -14:7

x= -7

Vậy...

Answer 2

b) 6x - ( -5) =17

6x + 5 =17

6x =17-5

6x= 12

x= 12:6

x=6

Vậy...

Answer 3

c) (x + 2) . (x - 9) = 0

=> x+2 = 0 hoặc x-9 =0

Nếu x+2 = 0 thì x = 0-2 =>x =-2

Nếu x-9 = 0 thì x= 0+9 => x= 9

Vậy...

Answer 4

\(\text{a, 7x = -14}\)

      \(\text{ x = (-14) }\div7\)

      \(\text{x = -2}\)

\(\text{b, 6x - (-5) = 17}\)

   \(\text{ 6x + 5 = 17}\)

   \(\text{ 6x = 17 - 5 }\)

   \(\text{ 6x = 12}\)

     \(\text{ x = }12\div6\)

     \(\text{ x = 2 }\)

\(\text{c, (x+2) . ( x-9) = 0}\)

\(\Rightarrow\)\(\orbr{\begin{cases}x+2=0\\x-9=0\end{cases}}\)\(\Rightarrow\)\(\orbr{\begin{cases}x=0-2\\x=0+9\end{cases}}\)\(\Rightarrow\)\(\orbr{\begin{cases}x=-2\\x=9\end{cases}}\)
\(\text{Vậy x=-2 hoặc x = 9}\)