mk giúp bạn chút thôi, nhiều quá

a)3x-55=-4²

3x-55=-16

3x=16+55

3x=71

x=71/3

b)(x+28)*3=51

x+28=51/3

x+28=17

x=17-28

x=-11

a) Ta có: \(18-x=58-\left(-30\right)\)

\(\Leftrightarrow18-x=88\)

\(\Leftrightarrow x=18-88=-70\)

Vậy: x=-70

b) Ta có: \(x-27=\left(-43\right)-9\)

\(\Leftrightarrow x-27=-43-9\)

\(\Leftrightarrow x-27=-52\)

\(\Leftrightarrow x=-25\)

Vậy: x=-25

c) Ta có: \(169-\left(x+4\right)=69\)

\(\Leftrightarrow x+4=169-69\)

\(\Leftrightarrow x+4=100\)

\(\Leftrightarrow x=96\)

Vậy: x=96

d) Ta có: \(\left(5x+3\right)-\left(-24+4\right)=33\)

\(\Leftrightarrow5x+3+24-4-33=0\)

\(\Leftrightarrow5x-10=0\)

\(\Leftrightarrow5x=10\)

\(\Leftrightarrow x=2\)

Vậy: x=2

e) Ta có: \(225-\frac{\left(5x+10\right)}{25}+5=-\left(-20\right)\)

\(\Leftrightarrow225-\frac{5x+10}{25}+5-20=0\)

⇔\(-\frac{5x+10}{25}+210=0\)

\(\Leftrightarrow-\frac{5x+10}{25}=-210\)

⇔\(\frac{5x+10}{25}=210\)

\(\Leftrightarrow5x+10=210\cdot25=5250\)

\(\Leftrightarrow5x=5250-10=5240\)

\(\Leftrightarrow x=1048\)

Vậy: x=1048

e) 225 - ( 5x +10 ) : 25 +5 =-(-20)

225 - ( 5x +10 ) : 25 +5 = 20

( 5x +10 ) : 25 +5 =225 - 20

( 5x +10 ) : 25 +5= 205

( 5x +10 ) : 25= 205-5

( 5x +10 ) : 25= 200

( 5x +10 ) = 200 x 25

5x +10 = 5000

5x = 5000 - 10

5x = 4990

x = 4990 : 5

x = 998

a) 18-x=58-(-30)

18 - x = 58 + 30

18 - x = 138

x = 18 - 138

x = - 120

b)x - 27 = (-43)-9

x - 27 = -52

x = -52 + 27

x= - 25

c)169 -( x +4) = 69

x + 4 = 169 - 69

x+4 =100

x = 100 - 4

x = 96

d)(5x +3 ) - (-24 +4 )=33

(5x +3) +20 =33

5x +3 = 33-20

5x +3 = 13

5x = 13 - 3

5x = 10

x =10 : 5

x = 2

x

mn bày e gấp vs ạ,e đag cần gấp lắm

ôi bạn ơi

mik ko bt

a. 800-{50.[18-2³) : 2 + 3²]}

= 800 - {50.[18 - 8) : 2 + 9]}

= 800 - {50.[10 : 2 + 9]}

= 800 - [50.(5 +9)]

= 800 - (50 . 14)

= 700

= 100

b. 28.(231+69) + 72.(131+169)

= 28.300 + 72.300

= 300 . (28 + 72)

= 300 . 100

= 30000

a) \(28.\left(231+69\right)+72.\left(169+31\right)=28.300+72.200\)

\(=100.\left(28.3+72.2\right)=100.\left(84+144\right)=100.228=22800\)

b) \(39.\left(250+87\right)+61\left(240+97\right)=39.337+61.337\)

\(=337.\left(39+61\right)=337.100=33700\)

a) 21 . 169 + (−69) . 21;
= 21 . [169 + (-69)
= 21 . 100 = 2100
b) 21 . (−25) . (−3) . (−4).
= [21 . (-3)] . [(-25) . (-4)]
= (-63) . 100 = -6300

a) =2100

b) = -6300

a) 21 . 169 + ($-$69) . 21

= 21 . [169 + ($-$69)]

= 21 . 100 = 2 100.

b) 21 . ($-$25) . ($-$3) . ($-$4)

= [21 . ($-$3)] . [($-$25) . ($-$4)]

= ($-$63) . 100 = $-$6 300.

K=28x(231+69)+72x(131+169)

K=28x300+72x300

K=(28+72)x300

K=100x300

K=30000

K = 28 . ( 231 + 69 ) + 72 . ( 131 + 169 )

K = 28 . 300 + 72 . 300

K = 300 . ( 28 + 72 )

K = 300 . 100

K = 30000

K = 28 ( 231 + 69 ) + 72 ( 131 + 169 )

K = 28 ( 231 + 69 ) + 72 ( 131 + 169 )

K = 28.300 + 72.300

K = ( 28 + 72 ).300

K = 100.300

K = 30000