Tim x thuoc Q biet;
a,|x| =2,1 ;b, |x| =-1 2/5
tim x thuoc z biet
a) (x-1)(x+2) < 0
b) (x+3)(x-5) > 0
a)Tim x, y thuoc Q biet:
(x-1)^2+(y+1)^2=0
b)Tim x, y biet:
2^x+1 × 3^y = 12^x
CMR
a, 10^+10^8+10^7 chia het cho 222
b, 81^7-27^9-9^13 chia het cho 45
tim x thuoc Q biet
a,{x+1} {x-2} < 0
b, {x-2} {x + 0,5} nhỏ hơn 0
a,tim x biet |x-2|+|3-2x|=2x+1
b,tim x,y thuoc Z biet xy+2x-y=5
c, tinh A=(1-1/15)(1-1/21)(1-1/28).....(1-1/210)
tim cac gia tri cua x thuoc Q , biet : ( x+1)(x-2)< 0
Tim x thuoc Q
a,(x+1)(x-2)<0
Tim x thuoc z biet:
A)(x-3)(2y+1)=7
B) (2x+1)(3y-2)=-55
tim x thuoc Z de A thuoc Z va tim gia tri do A=\(\frac{1-2x}{x+3}\)
