(4xX-0,8) :X+14,5=16
Tìm X:
4xX/1x5+4xX/5x9+4xX/9x13+4xX/13x17=16
\(\dfrac{4\times x}{1\times5}\) + \(\dfrac{4\times x}{5\times9}\) + \(\dfrac{4\times x}{9\times13}\) + \(\dfrac{4\times x}{13\times17}\) = 16
\(x\times\left(\dfrac{4}{1\times5}+\dfrac{4}{5\times9}+\dfrac{4}{9\times13}+\dfrac{4}{13\times17}\right)\) = 16
\(x\) \(\times\) (\(\dfrac{1}{1}\) - \(\dfrac{1}{5}\) + \(\dfrac{1}{5}\) - \(\dfrac{1}{9}\) + \(\dfrac{1}{9}\) - \(\dfrac{1}{13}\) + \(\dfrac{1}{13}\) - \(\dfrac{1}{17}\)) = 16
\(x\) \(\times\) ( \(\dfrac{1}{1}\) - \(\dfrac{1}{17}\)) = 16
\(x\) \(\times\) \(\dfrac{16}{17}\) = 16
\(x\) = 16 : \(\dfrac{16}{17}\)
\(x\) = 17
(3*x-0,8):x+14,5=15
[3*x-0,8] / x +14,5=15
(3x x- 0,8): x+ 14,5= 15
\(\left(3\times x-0,8\right)\div x+14,5=15\)
\(\Leftrightarrow\)\(\left(3\times x-0,8\right)\div x=15-14,5\)
\(\Leftrightarrow\)\(\left(3\times x-0,8\right)\div x=0,5\)
\(\Leftrightarrow\)\(3\times x-0,8=0,5\times x\)
\(\Leftrightarrow\)\(3\times x=0,5\times x+0,8\)
\(\Leftrightarrow\)\(3\times x-0,5\times x=0,8\)
\(\Leftrightarrow\)\(x\left(3-0,5\right)=0,8\)
\(\Leftrightarrow\)\(x\times2,5=0,8\)
\(\Leftrightarrow\)\(x=0,8\div2,5\)
\(\Leftrightarrow\)\(x=\frac{8}{25}=0,32\)
Cách 2:
\(\left(3\times x-0,8\right)\div x+14,5=15\)
\(\Leftrightarrow\)\(3-0,8\div x=0,5\)
\(\Leftrightarrow\)\(0,8\div x=3-0,5\)
\(\Leftrightarrow\)\(0,8\div x=2,5\)
\(\Leftrightarrow\)\(x=0,8\div2,5\)
\(\Leftrightarrow\)\(x=\frac{8}{25}=0,32\)
3 nhân x - 0,8/x +14,5 = 15
(3x x -0,8):x + 14,5 = 15
Tìm x biết [3xX-0,8]:X+14,5=15
(3*x-0,8):x+14,5=15
(3*x-0,8):x=15-14,5
3*x:x-0,8:x=0,5
3*1-0,8:x=0,5
3-0,8:x=0,5
0,8:x=3-0,5
0,8:x=2,5
x=0,8:2,5
x=0,32
Tim x biet : [ 3 x X - 0,8 ] : X + 14,5=15
[ 3 x X - 0,8 ] : x + 14,5 = 15
[ 3 x X ] : X = 15 - 14,5
[ 3 x X ] : X = 0,5
3 x X = 0,5 x X
3 x X - 0,5 x X = 0
X ( 3 - 0,5) = 0
2,5 x X = 0
X = 0: 2,5
X = 0
(3*x-0,8):x+14,5=15
(3*x-0,8):x=15-14,5
3*x:x-0,8:x=0,5
3*1-0,8:x=0,5
3-0,8:x=0,5
0,8:x=3-0,5
0,8:x=2,5
x=0,8:2,5
x=0,32
(3 x y-0,8):y+14,5=15
(3xy-0,8):y+14,5=15
(3xy-0,8):y=15-14,5
3xy:y-0,8:y=0,5
3x-0,8:y=0,5
Còn lại làm tiếp đi!