tìm x
(5.28 +x ) : 24 = 5.6
tìm x
(4.27 + x) : 2.4 =5.6
(4,27+x)=5,6x2,4
(4,27+x)=13,44
x=13,44-4,27
x=9,17
tk mình nha!
Tìm x:
a) 5.6-x+4.5=2.3
b) 1.7-4.6+x=0.6
a -x=2.3 -5.6 -4.5
-x = -7.8
x=7.8
b x = 0.6 -1.7 +4.6
x = 3.5
Tính nhanh:
a)38.105:5.38
b)2.169.12-3.68.8-24
c)(112+2.28-5.28):28
d)1448-(448+500)
a)38.105:5.38=(38:38).(105:5)
=1.21
=21
Oxi hóa 3.2 ancol metylic trong oxi vừa đủ thu 5.28 g hh sản phẩm X. Cho X tác dụng agno3/nh3 thu m g Ag. Các phản ứng hoàn toàn. Tính m?
tìm x biết:
1/3.4+1/4.5+1/5.6+1/6.7+....+1/x(x+1)
\(\frac{1}{3.4}+\frac{1}{3.4}+...+\frac{1}{x\left(x+1\right)}=\frac{1}{3}-\frac{1}{x+1}\)
\(\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+...+\frac{1}{x\left(x+1\right)}\)
\(=\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+.....+\frac{1}{x}-\frac{1}{x+1}\)
\(=\frac{1}{3}-\frac{1}{x+1}\)
1. tìm x
a) ( 3 x X - 7.5 ) + 2.3 = 5.6
b) 5 x X - 3 x X + 69 = 285
a) (3 x X - 7.5) + 2.3 = 5.6
3 x X - 7.5 = 5.6 - 2.3
3 x X - 7.5 = 3.3
3 x X = 3.3 + 7.5
3 x X = 10.8
X = 10.8 : 3
X = 3.6
b) 5 x X - 3 x X + 69 = 285
(5 - 3) x X = 285 - 69
2 x X = 216
X = 216 : 2
X = 108
a) ( 3 x X - 7.5 ) + 2.3 = 5.6
3 x X - 7.5 = 5.6 - 2.3
3 x X - 7.5 = 3.3
3 x X = 3.3 + 7.5
3 x X = 10.8
X = 10.8 : 3
X = 3.6
b) 5 x X - 3 x X + 69 = 285
(5 - 3) x X + 69 = 285
2 x X = 285 - 69
2 x X = 216
X = 216 : 2
X = 108
Tìm x
a)tìm x1/3.4+1/3.5+1/5.6+....+1/x.(x+1)=3/10
mấy bn jup mikk vs
Mình sửa đề luôn ^^
\(\frac{1}{3\cdot4}+\frac{1}{4\cdot5}+...+\frac{1}{x\left(x+1\right)}=\frac{3}{10}\)
\(\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+...+\frac{1}{x}-\frac{1}{x+1}=\frac{3}{10}\)
\(\frac{1}{3}-\frac{1}{x+1}=\frac{3}{10}\)
\(\frac{1}{x+1}=\frac{1}{30}\)
=> x + 1 = 30
=> x = 29
Vậy,..... @_@ ^^
tìm x, biết
1/3.4+1/4.5+1/5.6+1/6.7+...+1/x.(x+1)=3/10
(1/3-1/4+1/4-1/5+1/5-.......+1/x.(x+1)=3/10
1/3-1/x+1=3/10
tự làm...
tìm x biết:
1/3.4+1/4.5+1/5.6+1/6.7+....+1/x(x+1)=3/10
1/3.4+1/4.5+1/5.6+1/6.7+....+1/x(x+1)=3/10
<=> \(\frac{1}{3.4}+\frac{1}{4.5}+...+\frac{1}{\left(x+1\right)x}=\frac{1}{3}-\frac{1}{x+1}=\frac{3}{10}\)
<=> \(\frac{1}{x+1}=\frac{1}{3}-\frac{3}{10}=\frac{1}{30}\)=> x+1=30=>x=29
\(\frac{1}{3\cdot4}+\frac{1}{4\cdot5}+\frac{1}{5\cdot6}+\frac{1}{6\cdot7}+...+\frac{1}{x\left(x+1\right)}=\frac{3}{10}\)
\(\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+...+\frac{1}{x}-\frac{1}{x+1}=\frac{3}{10}\)
\(\frac{1}{3}-\frac{1}{x+1}=\frac{3}{10}\)
\(\frac{1}{x+1}=\frac{1}{3}-\frac{3}{10}\)
\(\frac{1}{x+1}=\frac{1}{30}\)
\(\Rightarrow x+1=30\)
\(x=30-1=29\)