Bài 1 :

a) (-123) + |-13| + (-7)

b) |-10| + |45| + (-|-455|) + |-750|

c) -|-33| + (-15) + 20 - |45-40| - 57

Bài 2 :

a) (x - 6)² = 9

b) 35 - 3.|x| = (2³ - 4)

c) |x| + |-5| = |-45|

d) 6.x + x = 5¹¹ : 5⁹ + 3¹

e) 7.x - x = 5²¹ : 5¹⁵ + 3.2² - 7⁰

f ) 2^x : 2⁵ = 1

g) 2^x+1.2²⁰¹⁴ = 2²⁰¹⁵

h) | x - 5 | = 7 - (-3)

i) | - x - 16| = 31

k) \(150⋮x;84⋮x;30⋮x\) và 0 < x < 16 (\(x\in N\)) \(x⋮12;x⋮15;x⋮18\)

l) \(x⋮12;x⋮15;x⋮18\) và x < 150 (\(x\in N\))

a, 5+(-12)-10=................................................................

b, 25-(-17)+24-12=.......................................................................

c, 5⁶/5⁴+2³*2²-225/15^{2=........................................................................................................}

d, (-5-3)*(3-5)/(3-5)=........................................................................................

e, 4*(13-16)-(3-5)*(-3)²=.............................................................................................

Tìm x :
a ) 7 ( x-4 ) = 7⁴ : 73
b ) 2x-105 : 21=15
c ) 15-5 ( x- 1 ) = 10
d )  ( x-12 ) :3 = 6
e ) 24 + 5 . x = 7⁵ : 7³
g ) x + 12.3=40
h ) 2x-138=2³.3²
i ) 231- ( x-6 ) = 1339 : 13
k ) 3x + 2x = 25
l )  2x-4² : 8 = 12
m ) 12 ( x-1 ) :3=4³- 2³
n ) 128 : ( x-1 )² =2
o ) x-34=2.3²-1
ô ) 3+2^x-1 = 24 - [ 4² -(2²-1 ) ]
Viết gọn tổng sau :
A = 3+3²⁺ 3³ + 3⁴+......+3⁹⁹+3¹⁰⁰
So sanh :

 A = 1=2+2²+2³+2⁴+.....+2⁴⁹ và 2⁵⁰