Question

Bài 1: Tìm số Nguyên x biết:

A,x-12=(-9)-15

B,2-x=17-(-5)

C,11-(15+11)=x-(25-9)

D,x-(17-x)=x-7

E,9-25=(7-x)-(25+7)

G,x-13=21-x

Giúp mình với mình cần gấp lắm!!!

 

Answer 1

a) Ta có: \(x-12=\left(-9\right)-15\)

\(\Rightarrow x-12=-24\)

\(\Rightarrow x=-12\)

b) \(2-x=17-\left(-5\right)\)

\(\Rightarrow2-x=22\)

\(\Rightarrow x=2-22\)

\(\Rightarrow x=-20\)

c) \(11-\left(15+11\right)=x-\left(25-9\right)\)

\(\Rightarrow-15=x-16\)

\(\Rightarrow x=1\)

d) \(x-\left(17-x\right)=x-7\)

\(\Rightarrow x-17+x=x-7\)

\(\Rightarrow x+x-x=-7+17\)

\(\Rightarrow x=10\)

e) \(9-25=\left(7-x\right)-\left(25+7\right)\)

\(\Rightarrow9-25=7-x-25-7\)

\(\Rightarrow-16=-25-x\)

\(\Rightarrow x=-9\)

g) \(x-13=21-x\)

\(\Rightarrow x+x=21+13\)

\(\Rightarrow2x=34\)

\(\Rightarrow x=17\)

Answer 2

a, x - 12 = ( -9 ) - 15 

x - 12 = -24

x = -24 + 12

x = -12

b, 2 - x = 17 - ( -5 )

2 - x = 22

x = 2 - 22

x = -20

c, 11 - ( 15 + 11 ) = x - ( 25 - 9 )

11 - 26 = x - 16

-15 = x - 16

x = -15 + 16 

x = 1

d, x - ( 17 - x ) = x - 7

x - 17 + x = x - 7

x + x - 17 = x - 7

x + x - x = -7 + 17

x = 10

e.9 - 25 = ( 7- x ) - ( 25 + 7 )

-16 = ( 7 - x ) -32

7 - x = -32 + 16 

7 - x = 16

x = 7 - 16

x= -9

g, x - 13 = 21 - x

x + x = 21 + 13

2x = 44

x = 44 : 2

x=22

Answer 3

A= -12

B=-20

C=1

D=17

E=-9

G=17

Answer 4

\(a,x-12=\left(-9\right)-15\)

    \(x-12=-24\)

                \(x=-24+12\)

                \(x=-12\)

\(b,2-x=17-\left(-5\right)\)

    \(2-x=17+5\)

    \(2-x=22\)

             \(x=2-22\)

             \(x=-20\)

\(c,11-\left(15+11\right)=x-\left(25-9\right)\)

                             \(-15=x-16\)

                                    \(x=-15+16\)

                                    \(x=1\)

\(d,x-\left(17-x\right)=x-7\)

         \(x-17+x=x-7\)

               \(2x-17=x-7\)

                  \(2x-x=-7+17\)

                             \(x=10\)

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