1. Tìm x\(\in\)Z 

a) (x:3).(x+2)>0

b) ( x+1)+(x+2)+(x+5)+...+(x+99)=0

c) (x-3)+(x-2)+(x-1)+...+(10+11)1=11

1. Tìm x\(\in\)Z 

a) (x:3).(x+2)>0

b) ( x+1)+(x+2)+(x+5)+...+(x+99)=0

c) (x-3)+(x-2)+(x-1)+...+(10+11)1=11

1. Tìm x\(\in\)Z 

a) (x:3).(x+2)>0

b) ( x+1)+(x+2)+(x+5)+...+(x+99)=0

c) (x-3)+(x-2)+(x-1)+...+(10+11) = 11

Làm ơn giúp nka gấp rồi =_=

1. Tìm x\(\in\)Z 

a) (x:3).(x+2)>0

b) ( x+1)+(x+2)+(x+5)+...+(x+99)=0

c) (x-3)+(x-2)+(x-1)+...+(10+11)1=11

2. Tính nhanh

\(A=\frac{1}{1.4.7}+\frac{1}{4.7.10}+...+\frac{1}{54.57.60}\)

1. Tìm x\(\in\)Z 

a) (x:3).(x+2)>0

b) ( x+1)+(x+2)+(x+5)+...+(x+99)=0

c) (x-3)+(x-2)+(x-1)+...+(10+11)1=11

Có ai giúp mình ko vậy nek

tìm x\(\in\)Z

a)(x+1)+(x+3)+(x+5)+...+(x+99)=0

b)(x-3)+(x-2)+(x-1)+...+10+11=11

Tìm x \(\in\)Z ,biết:

a,\(\left(x+1\right)+\left(x+3\right)+...+\left(x+99\right)=0\)

b,\(\left(x-3\right)+\left(x-2\right)+\left(x-1\right)+...+10+11=11\)

1. Tìm x\(\in\)Z 

a) (x:3).(x+2)>0

b) ( x+1)+(x+2)+(x+5)+...+(x+99)=0

c) (x-3)+(x-2)+(x-1)+...+(10+11)1=11

 Bài 1 tính nhanh

a. 1 + 3 - 5 - 7 + 9 +11 - ... - 397 -399

b . 3 \(^{100}\) - 3 \(^{99}\) - 3 \(^{98}\)- ... - 3 \(2\) - 3 - 1

bài 2 tìm x

a ./ 2x - 2/ = x + 18

b ( x + 99 ) \(^2\) = 0

c. x + ( x + 1 ) + ( x + 2 ) + ( x + 3 ) + ... + 35 = 0