Tìm x
\(\left(2\frac{4}{5}.x+50\right):\frac{2}{3}=-51\)
Giúp mình với tối nay mik đi hc rùi
giúp mik với, t4 mik đi hc rùi
\(\left(1+\frac{1}{1.3}\right)\left(1+\frac{1}{2.4}\right)\left(1+\frac{1}{3.5}\right).......\left(1+\frac{1}{2014.2016}\right)=\frac{x}{1008}\)
giúp mik với, t4 mik đi hc rùi
\(\left(1+\frac{1}{1.3}\right)\left(1+\frac{1}{2.4}\right)\left(1+\frac{1}{3.5}\right).....\left(1+\frac{1}{2014.2016}\right)=\frac{x}{1008}\)
Gọi công thức tổng quát là: \(1+\frac{1}{x\left(x+2\right)}=\frac{x^2+2x+1}{x\left(x+2\right)}=\frac{\left(x+1\right)^2}{x\left(x+2\right)}\)
Khi đó vế trái là:
\(\frac{2^2}{1.3}.\frac{3^2}{2.4}.\frac{4^2}{3.5}.....\frac{2015^2}{2014.2016}\)
Rút gọn ta được:
\(\frac{2.2015}{1.2016}=\frac{2015}{1008}\)
Thay vào PT ta được:
\(\frac{2015}{1008}=\frac{x}{1008}\)\(\Rightarrow x=2015\)
\(4-\left(x-\frac{1}{2}\right)-3\left(5-x\right)=0\)
Kết quả bằng 0 nhé
Tìm x
Giúp với 7h mik nộp bài rùi
minh co gang lam tung buoc nho cho ban hieu.
\(4-\left(x-\frac{1}{2}\right)-3\left(5-x\right)=0\)
{nhan pp pha ngoac
\(4-x+\frac{1}{2}-3.5+3.x=0\)
{gom cac so hang, hang so chuyen ben tay phai}
\(\left(3x-x\right)=3.5-4-\frac{1}{2}=15-4-\frac{1}{2}=11-\frac{1}{2}=\frac{21}{2}\)
\(2x=\frac{21}{2}\Rightarrow x=\frac{21}{2}:\frac{2}{1}=\frac{21}{2}.\frac{1}{2}=\frac{21}{4}\)
\(x=\frac{21}{4}\)
Tìm x:
a, x + 30%x = -1,31
b,\(\left(x-\frac{1}{2}\right):\frac{1}{3}+\frac{5}{7}=9\frac{5}{7}\)
c, \(\frac{1}{2}x-\frac{3}{4}=\frac{14}{9}.\frac{3}{7}\)
d,\(\frac{-5}{6}-x=\frac{7}{12}+\frac{-1}{3}\)
e,\(\frac{x+3}{-15}=\frac{1}{3}\)
f,\(\left(4,5-2x\right).\left(-1\frac{4}{7}\right)=\frac{11}{14}\)
GIÚP MIK LM TRONG TỐI NAY NHA, MAI MIK PHẢI NỘP RỒI
\(a)x+30\%x=-1,31\)
\(\Leftrightarrow x+\frac{3x}{10}=-1,31\)
\(\Leftrightarrow10x+3x=-13,1\)
\(\Leftrightarrow13x=-13,1\Leftrightarrow x=-\frac{131}{130}\)
\(b)\left(x-\frac{1}{2}\right):\frac{1}{3}+\frac{5}{7}=9\frac{5}{7}\)
\(\Leftrightarrow\frac{2x-1}{2}.3+\frac{5}{7}=\frac{68}{7}\)
\(\Leftrightarrow\frac{6x-3}{2}=\frac{63}{7}\)
\(\Leftrightarrow\frac{6x-3}{2}=9\)
\(\Leftrightarrow6x-3=18\)
\(\Leftrightarrow x=\frac{7}{2}\)
\(c)\frac{1}{2}x-\frac{3}{4}=\frac{14}{9}.\frac{3}{7}\)
\(\Leftrightarrow\frac{x}{2}-\frac{3}{4}=\frac{2}{3}\)
\(\Leftrightarrow\frac{x}{2}=\frac{17}{12}\)
\(\Leftrightarrow12x=34\Leftrightarrow x=\frac{17}{6}\)
(\(\left(3\frac{1}{2}+2x\right).2\frac{2}{3}=5\frac{1}{3}\)
/2x+3/=5
\(\frac{x-2}{4}=\frac{5+x}{3}\)
các bạn giúp mik nha mai mik kiểm tra rùi
\(\left(3\frac{1}{2}+2x\right).2\frac{2}{3}=5\frac{1}{3}\)
<=>\(\left(\frac{7}{2}+2x\right).\frac{8}{3}=\frac{16}{3}\)
<=>\(\frac{28}{3}+\frac{16x}{3}=\frac{16}{3}\)
<=>\(\frac{16x}{3}=\frac{-2}{3}\)
<=>\(16x=-2\)
<=>\(x=\frac{-1}{8}\)
vậy \(x=\frac{-1}{8}\)
b,\(\left|2x+3\right|=5\)
xét x<0,ta co: \(\left|2x+3\right|=5\)<=> \(-2x+3=5\)<=>\(-2x=2\)<=>\(x=-1\)(loại)
xét x>0,ta co:\(\left|2x+3\right|=5\)<=>\(2x+3=5\)<=>\(2x=2\)<=>\(x=1\)
c,\(\frac{x-2}{4}=\frac{5+x}{3}\)
<=>\(\frac{3x-6}{12}=\frac{20+4x}{12}\)
=>\(3x-6=20+4x\)
<=>\(3x-6-20-4x=0\)
<=>\(-x-26=0\)
<=>\(-x=26\)
<=>\(x=-26\)
kl:.......
Chứng Minh Rằng
\(\left(1+\frac{1}{2^1}\right)\left(1+\frac{1}{2^2}\right)\left(1+\frac{1}{2^3}\right)...\left(1+\frac{1}{2^{2020}}\right)< 3\)
Giúp mình với tối nay mình đi học rồi.
Tìm x, biết:
b)3/x+4/-/2x+1/-5/x+3/+/x-9/=5
c)\(\left|\frac{11}{5}-x\right|+\left|x-\frac{1}{5}\right|+\frac{41}{5}=1,2\)
d)\(2\left|x+\frac{7}{2}\right|+\left|x\right|-\frac{7}{2}=\left|\frac{11}{5}-x\right|\)
CÁC BẠN GIÚP GIÚP MIK GIẢI BÀI NÀY VỚI, MI ĐANG GẤP LẮM!!!
MIK SẼ TICK CHO...PLEASE!!!
Tìm x; y sao cho :
a, \(\left|x\left(x^2-3\right)\right|=x\)
b, x+3.y = 4.x.y = x:y
c, \(\frac{x}{3}+\frac{1}{y}=\frac{1}{2}\)
Các bạn giúp mình với Mai mình pải nộp bài rùi !!!!!
a) Vì \(\left|x\left(x^2-3\right)\right|\ge0\) nên \(x\ge0\)
Ta có : |x(x2 - 3)| = x
<=> x(x2 - 3) = x <=> x2 - 3 = x : x = 1 <=> x2 = 4
Vì x \(\ge\) 0 nên x = 2
\(\frac{1}{4}+\frac{1}{3}\left(2x-1\right)=-5\)
\(\frac{2}{3}x-\frac{1}{2}=\frac{1}{10}\)
\(\left(x.6\frac{2}{7}+\frac{3}{7}\right).2\frac{1}{5}-\frac{3}{7}=-2\)
\(5\frac{4}{7}:x=13\)
\(\left(2\frac{4}{5}x-50\right):\frac{2}{3}=51\)
làm hộ mik nhanh vs ... mik chỉ còn 50p nữa là nộp pài r