a, => x . (-x) = -2 : \(\frac{8}{25}\)
=> - (x2) = - \(\frac{16}{25}\)
=> \(-\left(x^2\right)=-\left[\left(\frac{4}{5}\right)^2\right]\)
=> \(x=\frac{4}{5}\)
b, => \(\left(x-1\right):2=\frac{5}{4}\)
=> \(x-1=\frac{5}{4}.2\)
=> \(x-1=\frac{5}{2}\)
=> \(x=\frac{5}{2}+1\)
=> \(x=\frac{7}{2}\)
tim x ; a) \(\left(\frac{1}{16}\right)^x=\left(\frac{1}{2}\right)^{10}\)
b) \(\frac{8}{25}=\frac{2^x}{5^{x-1}}\)
1 tim x \(2014.\left|x-12\right|+\left(x-12\right)^2=2013.\left|12-x\right|\)\(x\)|
2 chung minh \(8^7-2^{18}⋮14\)
3 tim x,y,z biet 4x=7y=3z va x+y+z=61
4 tim a,b,c biet \(\frac{1}{2}a=\frac{2}{3}b=\frac{3}{4}c\)vs \(a-b=15\)
giup mk nha moi nguoi,lm dc cang nhiu cang tot
Bai 1:a)Tim x biet\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x\times\left(x+1\right)}=\frac{2009}{2011}\)
b)\(\left(x-1\right)\times f\left(x\right)=\left(x+4\right)\times f\left(x\right)\)voi moi x
Bai 2;Tim x;y;z biet a)\(\frac{y+z+1}{x}=\frac{x+z+2}{y}=\frac{x+y-3}{z}\) b)\(\frac{2x+1}{5}=\frac{3y-z}{7}=\frac{2x+3y-1}{6x}\)
Tim x biet neu \(\frac{x-2}{\left(a+3\right)\left(a-5\right)}=\frac{1}{2\left(a+3\right)}+\frac{1}{2\left(a+5\right)}\)
va x khac -3;5
Tim x, biet:
a/ \(3,8:\left(2.x\right)=\frac{1}{4}:2\frac{2}{3}\)
b/ \(\left(0,25.x\right):3=\frac{5}{6}:0,125\)
c/ \(0,01:2,5=\left(0,75.x\right):0,75\)
d/ \(1\frac{1}{3}:0,8=\frac{2}{3}:\left(0,1.x\right)\)
tim x
\(a,\left(x-1\right)^2=\left|\frac{1}{4}-\frac{1}{2}-\frac{3}{4}\right|\)
b , \(\left(x^x-8\right).\left(x^2-15\right)< 0\)
BT2: Tim x
\(1.\left(3x+1\right)^2=25\)
\(2.\left[x-\frac{1}{2}\right]+\frac{1}{2}=\frac{5}{8}\)
\(3.\left[x+\frac{3}{4}\right]-\frac{1}{3}=0\)
\(4.\frac{1}{9}.3^4.3x=3^7\)
\(5.\frac{x}{5}=\frac{4}{21}\)
Tim x biet
\(\frac{3}{\left(x+2\right)\left(x+5\right)}+\frac{5}{\left(x+5\right)\left(\right)x+10}+\frac{7}{\left(x+10\right)\left(x+17\right)}=\frac{x}{\left(x+2\right)\left(x+17\right)}\)
tìm x,biết:
a)\(\frac{2}{\left(x+2\right)\left(x+4\right)}+\frac{4}{\left(x+4\right)\left(x+8\right)}+\frac{6}{\left(x+8\right)\left(x+14\right)}=\frac{x}{\left(x+2\right)\left(x+14\right)}\)
b)\(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)
c)\(\left(x+2\right)^2=\frac{38}{25}+\frac{9}{10}-\frac{11}{15}+\frac{13}{21}-\frac{15}{28}+\frac{17}{36}-...+\frac{197}{4851}-\frac{199}{4950}\)
giúp tớ với,huhu