Question

Tìm số nguyên x

a) 0100 - (31 - x) = 40

b) 280 - (x - 140) : 35 = 270

c) ( 1900 - 2x) : 35 - 32 = 16

d) 2^2x-1 : 4 = 8^3

e) (x + 2)^5 = 2^10

f) (3x - 4) . (x - 1)^3 = 0

g) (-2x + 1)^2 = 49

h) 1+2+3+...+x = 78

Answer 1

a: =>31-x=60

=>x=-29

b: =>(x-140):35=280-270=10

=>x-140=350

=>x=490

c: =>(1900-2x):35=48

=>1900-2x=1680

=>2x=220

=>x=110

d: =>\(2^{2x-1}=2^9\cdot2=2^{11}\)

=>2x-1=11

=>x=6

e: =>(x+2)^5=4^5

=>x+2=4

=>x=2

f: =>3x-4=0 hoặc x-1=0

=>x=4/3 hoặc x=1

g: =>(2x-1)^2=49

=>2x-1=7 hoặc 2x-1=-7

=>x=-3 hoặc x=4

h: =>x(x+1)/2=78

=>x(x+1)=156

=>x=12