Question

tìm x: 

a, -12 ( x- 5) + 7 ( 3 - x)= 5

b,-5 < x < 1

c,|x| < 3

d,(x - 3)(x - 5) < 0

e, 2x^2 - 3 = 29

g, -6x - (-7) = 25

h, 46 - ( x - 11) = -48

GIÚP VS, CHIỀU NAY MIK PHẢI NỘP RỒI

Answer 1

-12 .( x - 5 ) + 7 .( 3 - x ) = 5

-12x - ( -60 ) + 21 - 7x = 5

-12x + 60 + 21 - 7x = 5

( -12x - 7x ) + ( 60 + 21 ) = 5

-19x + 81 = 5

-19x = 5 - 81

-19x = -76

x = ( -76 ) : ( -19 )

x = 4

Answer 2

\(-5< x< 1\)

\(\Rightarrow\left\{-4;-3;-2;-1;0\right\}\)

Hok tốt

Answer 3

\(-5< x< 1\)

\(\Rightarrow x\in\left\{-4;-3;-2;-1;0\right\}\)

Hok tốt

Answer 4

\(\left|x\right|< 3\)

\(\Rightarrow\left|1\right|,\left|2\right|,\left|-1\right|,\left|-2\right|< 3\)

\(\Rightarrow x\in\left\{\pm1;\pm2\right\}\)

Hok tốt

Answer 5

\(2x^2-3=29\)

\(2x^2=29+3\)

\(2x^2=32\)

\(x^2=32:2\)

\(x^2=16\)

\(x^2=4^2\)

\(\Rightarrow x=4\)

Answer 6

\(-6x-\left(-7\right)=25\)

\(-6x=25+\left(-7\right)\)

\(-6x=18\)

\(x=18:\left(-6\right)\)

\(x=-3\)

Answer 7

\(46-\left(x-11\right)=-48\)

\(x-11=46-\left(-48\right)\)

\(x-11=94\)

\(x=94+11\)

\(x=105\)

Answer 8

a, -12x -60 +21 - 7x=5

     -12x -7x           = 5+60-21=44

-19x =44

x=\(\frac{-44}{19}\)

b,\(x\in-4,-3,-2,-1,0\)

c,| x |  < 3\(\Rightarrow x\in:-1;-2;0;1;2\)

e,\(2x^2=29+3=32\)

\(2x=32:2=16\)

\(x^2=16\Rightarrow x=-8;8\)

g, \(-6x+7=25\)

\(-6x=25-7=18\)    

\(x=18:\left(-6\right)=-3\)

h,\(46-x+11=-48\)

\(46-x=-48+\left(-11\right)=37\)

\(x=46-37=9\)

Answer 9

giúp tui lm ý d

Answer 10

a,  x= dell biết

b, x= số cần tìm

c, x= hỏi làm gì