Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
3,2 * X +0.25 =46
=> X = (46-0.25) / 3.2 =915/64
0.5/X * 0.04= 1
=> X= 0.5/1 /0.04= 25/2
\(\left(\frac{2}{3}+\frac{1}{3}:\frac{3}{4}+\frac{5}{9}\right).y-3=25\%+\frac{7}{4}\)
\(\Rightarrow\left(\frac{2}{3}+\frac{4}{9}+\frac{5}{9}\right).y-3=\frac{1}{4}+\frac{7}{4}\)
\(\Rightarrow\left(\frac{2}{3}+1\right).y-3=2\)
\(\Rightarrow\frac{5}{3}.y-3=2\)
\(\Rightarrow y-3=2:\frac{5}{3}\)
\(\Rightarrow y-3=\frac{6}{5}\)
\(\Rightarrow y=\frac{6}{5}+3\)
\(\Rightarrow y=\frac{21}{5}\)
Đề bài bạn viết sai phải là 2020 x 2016-4000 / 2016 x 2017 +2048
Ta có: 2020 x 2016 - 4000 = (2017+3) x 2016 -4000
= 2017 x 2016 + 3 x 2016 -4000
= 2017 x 2016 + 6048 -4000
= 2017 x 2016 + 2048
Vậy 2020 x 2016 - 4000 / 2017 x 2016 +2048 = 1
Chúc bạn học tốt.
\(\frac{2x-4,36}{0,125}=0,25.42,9-11,7.0,25+0,25.0,8\)
\(\Leftrightarrow\frac{2x-4,36}{0,125}=0,25.\left(42,9-11.7+0,8\right)\)
\(\Leftrightarrow\frac{2x-4,36}{0,125}=0,25.32\)
\(\Leftrightarrow\frac{2x-4,36}{0,125}=8\)
\(\Leftrightarrow2x-4,36=1\)
\(\Leftrightarrow2x=5,36\)
\(\Leftrightarrow x=2,68\)
b) \(N=\frac{1}{1.5}+\frac{1}{5.10}+\frac{1}{10.15}+\frac{1}{15.20}+...+\frac{1}{2005.2010}\)
\(\Leftrightarrow N=\frac{1}{5}\left(1-\frac{1}{5}+\frac{1}{5}-\frac{1}{10}+\frac{1}{10}-\frac{1}{15}+\frac{1}{15}-\frac{1}{20}+...+\frac{1}{2005}-\frac{1}{2010}\right)\)
\(\Leftrightarrow N=\frac{1}{5}\left(1-\frac{1}{2010}\right)\)
\(\Leftrightarrow N=\frac{1}{5}.\frac{2009}{2010}=\frac{2009}{10050}\)
Bài 1:
a)\(\frac{2\cdot x-4,36}{0,125}=0,25\cdot42,9-11,7\cdot0,25+0,25\cdot0,8\)
\(\frac{2\cdot x-4,36}{0,125}=0,25\cdot\left(42,9-11,7+0,8\right)\)
\(\frac{2\cdot x-4,36}{0,125}=0,25\cdot32\)
\(\frac{2\cdot x-4,36}{0,125}=8\)
\(2\cdot x-4,36=8\cdot0,125\)
\(2\cdot x-4,36=1\)
\(2\cdot x=1+4,36\)
\(2\cdot x=5,36\)
\(x=\frac{5,36}{2}=2,68\)
b) \(N=\frac{1}{1\cdot5}+\frac{1}{5\cdot10}+\frac{1}{10\cdot15}+\frac{1}{15\cdot20}+...+\frac{1}{2005\cdot2010}\)
\(4N=\frac{4}{1\cdot5}+\frac{4}{5\cdot10}+\frac{4}{10\cdot15}+\frac{4}{15\cdot20}+...+\frac{4}{2005\cdot2010}\)
\(4N=1-\frac{1}{5}+\frac{1}{5}-\frac{1}{10}+\frac{1}{10}-\frac{1}{15}+\frac{1}{15}-\frac{1}{20}+...+\frac{1}{2005}-\frac{1}{2010}\)
\(4N=1-\frac{1}{2010}=\frac{2009}{2010}\)
\(N=\frac{2009}{2010}\div4=\frac{2009}{8040}\)
Bài 2:
a) ( x + 5,2 ) : 3,2 = 4,7 ( dư 0,5 )
\(x+5,2=4,7\cdot3,2+0,5\)
\(x+5,2=15,54\)
\(x=15,54-5,2=10,34\)
b)\(A=\frac{4047991-2010\cdot2009}{4050000-2011\cdot2009}\)
\(A=\frac{4047991-2010\cdot2009}{4050000-2009-2010\cdot2009}\)
\(A=\frac{4047991-2010\cdot2009}{4047991-2010\cdot2009}=1\)
Bài 3:
a) \(104,5\cdot x-14,1\cdot x+9,6\cdot x=25\)
\(x\cdot\left(104,5-14,1+9,6\right)=25\)
\(x\cdot100=25\)
\(x=\frac{25}{100}=\frac{1}{4}=0,25\)
b) \(T=\frac{2009\cdot2010+2000}{2011\cdot2010-2020}\)
\(T=\frac{2009\cdot2010+2000}{2009\cdot2010+4020-2020}\)
\(T=\frac{2009\cdot2010+2000}{2009\cdot2010+2000}=1\)
X+0,24=46
=>X =46-0,24
=>x =48.76
0.5:Xx0,04=1
=>0,5:X =25
=>X =0.02
2)a): 2,85 * 156,23 - 2,85 * 56,23
=2,85 * ( 156,23 - 56,23 )
=2,85 * 100
= 285
2)b): = 1,5+(1,8+4,2)+(2,1+3,9)+(2,4+3,6)+(2,7+3,3)+3
= 1,5+(6+6+6+6)+3
=1,5+24+3
=28,5
Bài 1: Tìm y biết (14,17 - y) * 2/9 = 1/3
Bài 2: Tính nhanh
2,85 * 156,23 - 2,85 * 56,23
___________________________
1,5 + 1,8 + 2,1 + 2,4 + 2,7 + 3 + 3,3 + 3,6 + 3,9 +4,2
Bài 3: Tìm x
13,44 * x - (16 + x) * 0,5 - 3,7 * (x - 0,9) = 13,618
3,2xX+0,25=46
3,2xX=46-0,25
3,2xX=45,75
X=45,75:3,2
X=14,296875
0,5:Xx0,04=1
0,5:X=1:0,04
0,5:X=25
X=0,5:25
X=0,02
Ta có \(3,2\times x+0,25=46\)
\(\Rightarrow3,2\times x=46-0,25\)
\(\Rightarrow3,2\times x=45,75\)
\(\Rightarrow x=45,75\div3,2\)
\(\Rightarrow x=\frac{915}{64}\)
b, Ta có \(0,5\div x\times0,04=1\)
\(\Rightarrow0,5\div x=1\div0,04\)
\(\Rightarrow0,5\div x=25\)
\(\Rightarrow x=0,5\div25\)
\(\Rightarrow x=\frac{1}{50}\)