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\(8,75\times x+1,25\times x=20\)
\(\left(8,75+1,25\right)\times x=20\)
\(10\times x=20\)
\(x=20:10\)
\(x=2\)
Vậy \(x=2\)
Cjhucs bạn học tốt !!!
8,75x X + 1,25 x X = 20
X x ( 8,75 + 1,25 ) = 20
X x 10 = 20
X = 20 : 10
X = 2 Vậy X= 2
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3/5 - 1/3 x (2,48 + 0,52) x y : 60 : 5 = 1/5
1/3 x (2,48+0,52) x y : 60 : 5 = 2/5
1/3 x 3 x y : 60 : 5 = 2/5
y: 60 : 5 =2/5
y: 60 =2/5 x 5
y : 60 =2
y = 2 x 60
y =120
Ta có: \(\dfrac{3}{5}-\dfrac{1}{3}\left(2.48+0.52\right)\cdot y:60:5=\dfrac{1}{5}\)
\(\Leftrightarrow\dfrac{3}{5}-\dfrac{1}{3}\cdot3\cdot y\cdot\dfrac{1}{60}\cdot\dfrac{1}{5}=\dfrac{1}{5}\)
\(\Leftrightarrow y\cdot\dfrac{1}{300}=\dfrac{2}{5}\)
hay y=120
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\(\dfrac{1}{1\cdot2}+\dfrac{1}{2\cdot3}+\dfrac{1}{3\cdot4}+.......+\dfrac{1}{x\cdot\left(x+1\right)}=\dfrac{122}{123}\)
\(\Leftrightarrow1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+......+\dfrac{1}{x}-\dfrac{1}{x+1}=\dfrac{122}{123}\)
\(\Leftrightarrow1-\dfrac{1}{x+1}=\dfrac{122}{123}\)
\(\Leftrightarrow\dfrac{1}{x+1}=\dfrac{1}{123}\)
\(\Leftrightarrow x=122\)
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a) Tìm x
\(\frac{8}{5}+x=\frac{17}{3}\)
\(\Rightarrow x=\frac{17}{3}-\frac{8}{5}\)
\(\Rightarrow x=\frac{61}{15}\)
\(x-\frac{17}{14}=\frac{80}{11}\)
\(\Rightarrow x=\frac{80}{11}+\frac{17}{14}\)
\(\Rightarrow x=\frac{1307}{154}\)
b) Tính nhanh
\(52\times95+47\times95+95\)
\(=95\times\left(52+47+1\right)\)
\(=95\times100\)
\(=9500\)
\(a.\)\(\frac{8}{5}+x=\frac{17}{3}\)
\(\Leftrightarrow x=\frac{17}{3}-\frac{8}{5}\)
\(\Leftrightarrow x=\frac{85}{15}-\frac{24}{15}\)
\(\Leftrightarrow x=\frac{61}{15}\)
\(x-\frac{17}{14}=\frac{80}{11}\)
\(\Leftrightarrow x=\frac{80}{11}+\frac{17}{14}\)
\(\Leftrightarrow x=\frac{1120}{154}+\frac{187}{154}\)
\(\Leftrightarrow x=\frac{1307}{154}\)
\(b.\)Cách tính nhanh nhé:
\(52.95+47.95+95\)
\(=52.95+47.95+95.1\)
\(=95.\left(52+47+1\right)\)
\(=95.100\)
\(=9500\)
~ Rất vui vì giúp đc bn ~
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3*x + 2*x + x =12*5 + 12*4 + 12
3*x +2*x + x = 12*(5 + 4 +1)
3*x + 2*x + x = 12*10
3*x + 2*x + x = 120
x*(3 +2 + 1) = 120
x*6 = 120
x = 120 : 6
x = 20
nhanh lên nào
trả lời luôn ik