\(\left(x-5\right)\frac{30}{100}=\frac{20x}{100}+5\)
hỏi x bằng mấy
cả cách trình bày nữa
\(\left(X-5\right)\cdot\frac{30}{100}=\frac{20X}{100}+5\)
\(\left(x-5\right).\frac{30}{100}=\frac{20x}{100}+5\)
\(\Leftrightarrow\left(x-5\right).0,3=0,2.x+5\)
\(\Leftrightarrow0,3.x-1,5=0,2.x+5\)
\(\Leftrightarrow0,3.x-0,2.x=5+1,5\)
\(\Leftrightarrow0,1.x=6,5\)
\(\Leftrightarrow x=65\)
\(\frac{\left(x-5\right).30}{100}=\frac{20x}{100}+\frac{500}{100}\)
\(\frac{30x-150}{100}=\frac{20x+500}{100}\)
=> 30x - 150 = 20x + 500
30x - 20x = 500 + 150
10x = 650
x = 65
Tìm số tự nhiên x biết: \(\left(x-5\right)\frac{30}{100}=\frac{20x}{100}+5\)
tìm x biết rằng :
a) x - \(\left(\frac{50x}{100}+\frac{25x}{200}\right)=11\frac{1}{4}\) c) ( x - 5 ) . \(\frac{30}{100}=\frac{20x}{100}+5\)
a) x-\(\left(\frac{50x}{100}+\frac{25x}{200}\right)\)=\(11\frac{1}{4}\)
<=>x - \(\frac{1}{2}x-\frac{1}{8}x\)=\(\frac{11.4+1}{4}\)
<=>\(\frac{3}{8}x=\frac{45}{4}\)
<=>x=\(\frac{45}{4}:\frac{3}{8}\)
<=>x=30
Vậy x=30
c) (x-5).\(\frac{30}{100}\)=\(\frac{20x}{100}+5\)
<=>(x-5).\(\frac{3}{10}\)=\(\frac{x}{5}\)+5
<=>\(\frac{3x}{10}-\frac{15}{10}=\frac{x}{5}+5\)
<=>\(\frac{3x}{10}-\frac{x}{5}=5+\frac{15}{10}\)
<=>\(\frac{x}{10}=\frac{13}{2}\)
<=>x=\(\frac{13.10}{2}\)
<=>x=65
Vậy: x=65
|x|+4x=6
(x+4)=y(x+1)
\(\left(x-5\right)\frac{30}{100}=\frac{20x}{100}+5\)
Tìm số tự nhiên x, biết: \(\left(x-5\right)\frac{30}{100}=\frac{20x}{100}+5\)
Ta có: \(\left(x-5\right)\frac{30}{100}=\frac{20x}{100}+5\)
\(\Rightarrow\left(x-5\right)\frac{3}{10}=\frac{x}{5}+5\)
\(\Rightarrow\frac{3x-15}{10}=\frac{25+x}{5}\)
\(\Rightarrow5\left(3x-15\right)=10\left(25+x\right)\)
\(\Rightarrow15x-75=250+10x\)
\(\Rightarrow15x-10x=250+75\)
\(\Rightarrow5x=325\Rightarrow x=\frac{325}{5}=65\)
\(\left(x-8\right).\frac{3}{10}=\frac{1}{5}x+5\)
\(\frac{3}{10}x-\frac{3}{2}=\frac{1}{5}x+5\)
\(\frac{3}{10}x=\frac{1}{5}x+6,5\)
\(\Rightarrow\frac{1}{10}x=6,5\)
\(x=\frac{6,5}{\frac{1}{10}}\)
\(x=65\)
Vậy \(x=65\)
giải phương trình
a,\(\left(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+\frac{1}{9\cdot10}\right)\left(x-1\right)+\frac{1}{10}x=x-\frac{9}{10}\)
b,\(\frac{x+1}{1}+\frac{2x+3}{3}+\frac{3x+5}{5}+\frac{20x+39}{39}=22+\frac{4}{3}+\frac{6}{5}+\frac{40}{39}\)
c,(x-20)+(x-19)+(x-18)+...+100+101=101
a: \(\Leftrightarrow\left(1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+....+\dfrac{1}{9}-\dfrac{1}{10}\right)\cdot\left(x-1\right)+\dfrac{1}{10}x-x=-\dfrac{9}{10}\)
\(\Leftrightarrow\dfrac{9}{10}x-\dfrac{9}{10}-\dfrac{9}{10}x=-\dfrac{9}{10}\)
=>-9/10=-9/10(luôn đúng)
b: \(\Leftrightarrow\dfrac{195x+195+130x+195+117x+195+100x+195}{195}=\dfrac{22\cdot39+4\cdot65+6\cdot39+40\cdot5}{195}\)
=>347x+780=1552
=>347x=772
hay x=772/347
Cho \(\left(\frac{5x+2}{x^2-10}+\frac{5x-2}{x^2+10}\right).\frac{x^2-100}{x^2+4}\)
a, Tìm giá trị x để biểu thức được xác định
b, Rút gọn
c, tính giá trịA tại x = 20040
trình bày cách làm rõ ràng nữa nha
Tìm số tự nhiên \(x\), biết:
\(\left(x-5\right)\frac{30}{100}=\frac{20x}{100}+5\)
Tìm x
a, \(\frac{x-4}{x+1}=\frac{x-15}{x+6}\left(x\ne1,x\ne-6\right)\)
b, \(\left(6x-3\right).\left(4x-2\right)-3x+7=24x-5.\left(x+1\right)\)
trình bày cách làm nữa nha
a) Ta có: \(\frac{x-4}{x+1}=\frac{x-15}{x+6}\)
\(\Rightarrow\)\(x^2+6x-4x-24=x^2-15x+x-15\)(nhân chéo)
\(\Rightarrow x^2+2x-24=x^2-14x-15\)
\(\Rightarrow16x=9\)
\(\Rightarrow x=\frac{9}{16}\)