1 tim cac so nguyen x,y biet x/7=6/21 -5/y=20/28 1/2=x/12 x/8=-28/32 3/y=12/24 3/4=15/y 2 viet 3 phan so bang phan so -10/15
tim x biet :3/[x+2][x+5]+5[x+5][x+10]+7/[x+10][x+15]=x/[x+12][x+17]
Tim x biet 4/15 +1/6-5/9 > 2/3-x-3/4
Ai dung 5 sao lun
Tim x, y biet
\(x-\frac{3}{5}=\frac{3}{5}\)
\(|x|-\frac{4}{5}=\frac{2}{5}\)
\(\frac{x}{-5}=\frac{24}{15}\)
\(\frac{x}{4}=\frac{y}{5}vax-y=21\)
1)tim x biet rang:
a)3^x-1=1/243
b)2^x+2^x+3=144
c)81^-2x.27x=9^5
2)tim tiep so ghang thu 5 cua day so sau:-1/a^2;2/a^3;-6/a^4;24/a^5;...
3)tim so tu nhien x biet :
a)4^x+4^x+3=4160
b)2^x-1+5.2^x-2=7/32
tim x biet 5/4*(x-8)=-5/3(14-1/2)
tim x biet |2x+3|-2|4-x|=5
tim x biet (2x-3)^2-4(x+1)^2=5
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)