Tĩm,y,z biết:

a)\(\dfrac{12x-15y}{7}\)=\(\dfrac{20z-12x}{9}\)=\(\dfrac{15y-20z}{11}\)và x+y+z=48

b)\(\dfrac{x+16}{9}\)=\(\dfrac{y-25}{16}\)=\(\dfrac{z+9}{25}\) và \(^{2x^3}\)-1=15

c)\(\dfrac{x}{y+2+1}\)=\(\dfrac{y}{z+x+1}\)=\(\dfrac{z}{x+y-2}\)=x+y+z

d)\(\dfrac{3}{5}\)x=\(\dfrac{2}{3}\)y và \(^{x^2}\)-\(^{y^2}\)= 38

e)\(\dfrac{y+2+1}{x}\)=\(\dfrac{z+x+2}{y}\)=\(\dfrac{x+y+3}{z}\)=\(\dfrac{1}{x+y+z}\)

f)\(\dfrac{1+2y}{18}\)=\(\dfrac{1+4y}{24}\)=\(\dfrac{1+6y}{6x}\)

a) Cho \(\dfrac{a}{b}\)=\(\dfrac{b}{c}\)=\(\dfrac{c}{d}\)

CMR:(\(\dfrac{a+b+c}{b+c+d}\))\(^3\)=\(\dfrac{a}{d}\)

b)Cho \(\dfrac{a1}{a2}\)=\(\dfrac{a2}{a3}\)=\(\dfrac{a3}{a4}\)=...=\(\dfrac{a2008}{a2009}\)

CMR: \(\dfrac{a1}{a2009}\)=(\(\dfrac{a1+a2+a3+...+a2008}{a2+a3+a4+...+a2009}\))\(^{2008}\)

c) Cho \(\dfrac{a}{2003}\)=\(\dfrac{b}{2004}\)=\(\dfrac{c}{2005}\)

CMR: 4(a-b)(b-c)=(c-a)\(^2\)

nêu đời sống của cá?
help me!mai ktra r

Tìm x biết

a) |x+5| + |x-3|=9

b)|x+1| + |x-2| +|x+3|=6

c) |x-2|+|x+3|+|x-4|=2

d) 2|x+2|+|4-x|=22

e)|x-2|+|x-3|+2x-8|=9

f)3x|x+1|-2x|x+2|=12

g)|x-1|+3|x-3|-2|x-2|

lm giúp mình với mk đag cần gấp!HEPL MEEEE