\(...\Rightarrow\left(2x-6\right)=4^9:4^7\)

\(\Rightarrow2x-6=4^2\)

\(\Rightarrow2x-6=16\)

\(\Rightarrow2x=22\)

\(\Rightarrow x=11\)

(2x-6). 4⁷ = 4⁹

2x-6        = \(\dfrac{4^9}{4^7}\)

2x           = 16+6

x             = \(\dfrac{22}{2}\)

x             = 11

a) | 5-x |=| 15-47|

 | 5-x |=32

=> 5-x=32 hoặc 5-x=-32

*Nếu 5-x=32 => x=5-32=-27

*Nếu 5-x=-32 => x=5-(-32)=37

b) x=4 hoặc x=-4

c) 5. ( x-3)²=125

( x-3)² = 125:5

( x-3)² = 25

( x-3)² = 5²

=> x-3=5 => x=5+3=8

d) 49-( 2x-1)²=0

( 2x-1)² = 49-0

( 2x-1)² = 49

( 2x-1)² = 7²

=> 2x-1=7

2x=7+1

2x=8

x=8:2

x=4

tick nha (chi tiết lắm đó)

  1-2+3-4+5-6+...+47-48+49-50

= (1-2)+(3-4)+(5-6)+...+(47-48)+(49-50) có 25 số hạng

=-1 . 25

=-25

xin like

1, 42 x 53 + 47 x 156 - 47 x 114

= 42 x 53 + 47 x ( 156 - 114 ) 

= 42 x 53 + 47 x 42

= 42 x ( 53 + 47 ) 

= 42 x 100

= 4200

2, 53 x ( 51 + 4 ) + 53 x ( 49 + 96 ) + 53 

= 53 x 51 + 53 x 4 + 53 x 49 + 53 x 96

= 53 x ( 51 + 49 ) + 53 x ( 96 + 4 ) + 53

= 53 x 100 + 53 x 100 + 53

= 5300 + 5300 + 53

= 10653

3, 42 x ( 15 + 96 ) + 6 x ( 25 + 4 ) x 7 

= 42 x 15 + 42 x 96 + 42 x 25 + 42 x 4 

= 42 x ( 15 + 25 ) + 42 x ( 96 + 4 )
= 42 x 40 + 42 x 100

= 42 x ( 100 + 40 )

= 42 x 140 

= 5880

Tk mk nha !! ~

42. 53 + 47. 156 - 47. 114 = 42.53 +47.(156-114)
                                          =42.53 +47. 42
                                          = 42(53+47)
                                          = 42.100     = 4200

53. ( 51 + 4 ) + 53. ( 49 + 96 ) + 53 = 53(51+4+49+96+1)

                                                        = 53. 201        = 10653

42. ( 15 + 96 ) + 6. ( 25 +4 ). 7 = 42. ( 15 + 96 ) + 42(25+4)

                                                  = 42(15+96+25+4)

                                                  = 42. 140         = 5880

 mk lm xong rồi add friend nha

1+3+5+7+...+47+49+...+(-2)+(-4)+(-6)+...+(-48)+(-50)

=(-2+1)+(-4+3)+...+(-50+49)

=(-1)+(-1)+(-1)+...+(-1) (25 số -1)

= -25

A = - ( 5 - 6 ) - ( 3 - 4 + 5 - 7 )

A = -5 + 6 - 3 + 4 - 5 + 7

A = ( 6 + 4 ) + ( -5 + (-5) ) + ( -3 + 7 )

A = 10 + (-10) + 4

A = 0 + 4

A = 4

P = ( 1 + 3 + 5 + ... + 47 + 49 ) - ( 2 + 4 + 6 + ... + 48 + 50 )

P = \(\frac{\left(1+49\right)\cdot\left(\left(49-1\right):2+1\right)}{2}\)  -  \(\frac{\left(2+50\right)\cdot\left(\left(50-2\right):2+1\right)}{2}\)

P = \(625-650\)

P = \(-25\)