1/2 : 3/5 - y = 1/3
Những câu hỏi liên quan
Tìm x,y thuộc N,biết
1) (x+1) (y+2) = 5
2) (x+1) (y+2) = 6
3) (x+2) (y+3) = 6
4) (x -1) (y+3) = 6
5) (x -1) (y -3) = 5
6) (x -2) (y -1) = 3
7) (x -2) (y -1) = 5
8) (x -3) (y+1) = 7
Mẫu : 1) (x+1) (y+2) = 5 nên (x+1) và (y+2) Ư(5) = {1;5}
Trường hợp 1: x+1 = 1 thì y+2 = 5 nên x=0 và y=3 trường hợp 2: x+1 = 5 thì y+2 = 1 nên x=0 và y=
Lưu ý: ở cả hai trường hợp,1 và 5 là các ước của 5 Mn làm giống mẫu giúp mình với ạ
Xem chi tiết
Thu gọn đa thức:C=5\(x^3\)\(y^2\)+3\(x^2\)\(y^3\) \(\dfrac{1}{3}\) \(x^4\) \(y^5\) - \(\dfrac{1}{7}\)+\(\dfrac{1}{2}\) \(x^2\)\(y^3\) - 3\(x^4\) \(y^5\)+ \(\dfrac{1}{3}\)-4\(x^3\) \(y^2\)
Xem chi tiết
\(C=5x^3y^2-4x^3y^2+3x^2y^3+\dfrac{1}{2}x^2y^3+\dfrac{1}{3}x^4y^5-3x^4y^5-\dfrac{1}{7}\)
\(=x^3y^2+\dfrac{7}{2}x^2y^3-\dfrac{8}{3}x^4y^5-\dfrac{1}{7}\)
Đúng 2
Bình luận (0)
giải các hệ phương trìnha dfrac{5}{x-1}+dfrac{1}{y-1}10dfrac{1}{x-1}-dfrac{3}{y-1}18b dfrac{5}{x+y-3}-dfrac{2}{x-y+1}8dfrac{3}{x+y-3}+dfrac{1}{x-y+1}dfrac{3}{2}c sqrt{x-1}-3sqrt{y+2}22sqrt{x-1}+5sqrt{y+2}15d dfrac{7}{sqrt{x-7}}-dfrac{4}{sqrt{y+6}}dfrac{5}{3}dfrac{5}{sqrt{x-7}}+dfrac{3}{sqrt{y+6}}dfrac{13}{6}e 7x^2+13y-395x^2-11y33f 2left(x-1right)^2-3y^375left(x-1right)^2+6y^34
Đọc tiếp
giải các hệ phương trình
a \(\dfrac{5}{x-1}+\dfrac{1}{y-1}=10\)
\(\dfrac{1}{x-1}-\dfrac{3}{y-1}=18\)
b \(\dfrac{5}{x+y-3}-\dfrac{2}{x-y+1}=8\)
\(\dfrac{3}{x+y-3}+\dfrac{1}{x-y+1}=\dfrac{3}{2}\)
c \(\sqrt{x-1}-3\sqrt{y+2}=2\)
\(2\sqrt{x-1}+5\sqrt{y+2}=15\)
d \(\dfrac{7}{\sqrt{x-7}}-\dfrac{4}{\sqrt{y+6}}=\dfrac{5}{3}\)
\(\dfrac{5}{\sqrt{x-7}}+\dfrac{3}{\sqrt{y+6}}=\dfrac{13}{6}\)
e \(7x^2+13y=-39\)
\(5x^2-11y=33\)
f \(2\left(x-1\right)^2-3y^3=7\)
\(5\left(x-1\right)^2+6y^3=4\)
a) Ta có: \(\left\{{}\begin{matrix}\dfrac{5}{x-1}+\dfrac{1}{y-1}=10\\\dfrac{1}{x-1}-\dfrac{3}{y-1}=18\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{5}{x-1}+\dfrac{1}{y-1}=10\\\dfrac{5}{x-1}-\dfrac{15}{y-1}=90\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\dfrac{16}{y-1}=-80\\\dfrac{1}{x-1}-\dfrac{3}{y-1}=18\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}y-1=\dfrac{-1}{5}\\\dfrac{1}{x-1}=18+\dfrac{3}{y-1}=3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=\dfrac{4}{5}\\x-1=\dfrac{1}{3}\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{4}{3}\\y=\dfrac{4}{5}\end{matrix}\right.\)
Đúng 1
Bình luận (0)
Bài 2: (đề 2) Tìm y
a) \(2\dfrac{2}{5}-y:2\dfrac{3}{4}=1\dfrac{1}{2}\) b) \(1\dfrac{1}{4}+2\dfrac{1}{5}\) x \(y=2\dfrac{3}{5}\)
c) \(2\dfrac{4}{5}-2\dfrac{1}{4}:y=\dfrac{3}{4}\) c) \(x:3\dfrac{1}{3}=2\dfrac{2}{5}+\dfrac{7}{10}\)
\(2\dfrac{2}{5}-y:2\dfrac{3}{4}=1\dfrac{1}{2}\\ \dfrac{12}{5}-y:\dfrac{11}{4}=\dfrac{3}{2}\\ y:\dfrac{11}{4}=\dfrac{12}{5}-\dfrac{3}{2}\\ y:\dfrac{11}{4}=\dfrac{9}{10}\\ y=\dfrac{9}{10}\times\dfrac{11}{4}=\dfrac{99}{40}\\ b,1\dfrac{1}{4}+2\dfrac{1}{5}\times y=2\dfrac{3}{5}\\ \dfrac{5}{4}+\dfrac{11}{5}\times y=\dfrac{13}{5}\\ \dfrac{11}{5}\times y=\dfrac{13}{5}-\dfrac{5}{4}\\ \dfrac{11}{5}\times y=\dfrac{27}{20}\\ y=\dfrac{27}{20}:\dfrac{11}{5}=\dfrac{27}{44}\)
Đúng 2
Bình luận (0)
\(c,2\dfrac{4}{5}-2\dfrac{1}{4}:y=\dfrac{3}{4}\\ \dfrac{14}{5}-\dfrac{9}{4}:y=\dfrac{3}{4}\\ \dfrac{9}{4}:y=\dfrac{14}{5}-\dfrac{3}{4}\\ \dfrac{9}{4}:y=\dfrac{41}{20}\\ y=\dfrac{9}{4}:\dfrac{41}{20}=\dfrac{45}{41}\\ c2,x:3\dfrac{1}{3}=2\dfrac{2}{5}+\dfrac{7}{10}\\ x:\dfrac{10}{3}=\dfrac{12}{5}+\dfrac{7}{10}\\ x:\dfrac{10}{3}=\dfrac{31}{10}\\ x=\dfrac{31}{10}\times\dfrac{10}{3}=\dfrac{31}{3}\)
Đúng 0
Bình luận (0)
a) \(...\Rightarrow\dfrac{12}{5}-y:\dfrac{11}{4}=\dfrac{3}{2}\)
\(\Rightarrow y:\dfrac{11}{4}=\dfrac{12}{5}-\dfrac{3}{2}\Rightarrow y:\dfrac{11}{4}=\dfrac{24}{10}-\dfrac{15}{10}\)
\(\Rightarrow y:\dfrac{11}{4}=\dfrac{9}{10}\Rightarrow y=\dfrac{9}{10}x\dfrac{11}{4}=\dfrac{99}{40}\)
b) \(...\Rightarrow\dfrac{5}{4}+\dfrac{11}{5}xy=\dfrac{13}{5}\Rightarrow\dfrac{11}{5}xy=\dfrac{13}{5}-\dfrac{5}{4}\)
\(\Rightarrow\dfrac{11}{5}xy=\dfrac{52}{20}-\dfrac{25}{20}\Rightarrow\dfrac{11}{5}xy=\dfrac{27}{20}\)
\(\Rightarrow y=\dfrac{27}{20}:\dfrac{11}{5}=\dfrac{27}{20}x\dfrac{5}{11}=\dfrac{27}{44}\)
c) \(...\Rightarrow\dfrac{14}{5}-\dfrac{9}{4}:y=\dfrac{3}{4}\Rightarrow\dfrac{9}{4}:y=\dfrac{14}{5}-\dfrac{3}{4}\)
\(\Rightarrow\dfrac{9}{4}:y=\dfrac{56}{20}-\dfrac{15}{20}\Rightarrow\dfrac{9}{4}:y=\dfrac{39}{20}\)
\(\Rightarrow y=\dfrac{9}{4}:\dfrac{39}{20}\Rightarrow y=\dfrac{9}{4}x\dfrac{20}{39}=\dfrac{15}{13}\)
d) \(...\Rightarrow x:\dfrac{10}{3}=\dfrac{12}{5}+\dfrac{7}{10}\Rightarrow x:\dfrac{10}{3}=\dfrac{24}{10}+\dfrac{7}{10}\)
\(\Rightarrow x:\dfrac{10}{3}=\dfrac{31}{10}\Rightarrow x=\dfrac{31}{10}x\dfrac{10}{3}=\dfrac{31}{3}\)
Đúng 0
Bình luận (0)
giải hệ pt (đặt ẩn phụ )
a) x+2/x+1 + 2/y-2 =6
5/x+1 -1/y-2 =3
b) 2/2x-y +3/x-2y =1/2
2/2x-y -1/x-2y =1/18
c) 2|x-6| +3|y+1| =5
5|x-6| -4|y+1| =1
d) |x| +|y-3| =1
y - |x| =3
a: \(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{x+1+1}{x+1}+\dfrac{2}{y-2}=6\\\dfrac{5}{x+1}-\dfrac{1}{y-2}=3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\dfrac{1}{x+1}+\dfrac{2}{y-2}=5\\\dfrac{5}{x+1}-\dfrac{1}{y-2}=3\end{matrix}\right.\)
=>x+1=1 và y-2=1/2
=>x=0 và y=5/2
b: \(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{4}{x-2y}=\dfrac{1}{2}-\dfrac{1}{18}=\dfrac{9}{18}-\dfrac{1}{18}=\dfrac{8}{18}=\dfrac{4}{9}\\\dfrac{2}{2x-y}=\dfrac{1}{18}+\dfrac{1}{x-2y}\end{matrix}\right.\)
=>x-2y=9 và 2/2x-y=1/18+1/9=1/18+2/18=3/18=1/6
=>x-2y=9 và 2x-y=12
=>x=5; y=-2
c: \(\Leftrightarrow\left\{{}\begin{matrix}10\left|x-6\right|+15\left|y+1\right|=25\\10\left|x-6\right|-8\left|y+1\right|=2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}23\left|y+1\right|=23\\\left|x-6\right|=1\end{matrix}\right.\)
=>|x-6|=1 và |y+1|=1
=>\(\left\{{}\begin{matrix}x\in\left\{7;5\right\}\\y\in\left\{0;-2\right\}\end{matrix}\right.\)
Đúng 3
Bình luận (0)
Bài 3: (Đề 2) Tìm y
a) \(2\dfrac{2}{5}:\) y x \(1\dfrac{3}{4}=\dfrac{7}{8}\) b)\(3\dfrac{2}{5}:y:1\dfrac{1}{4}=2\dfrac{3}{5}\) c) \(\dfrac{12}{5}-2\dfrac{2}{5}x\) y \(=1\dfrac{1}{4}\)
\(a,2\dfrac{2}{5}:y\times1\dfrac{3}{4}=\dfrac{7}{8}\\ \dfrac{12}{5}:y\times\dfrac{7}{4}=\dfrac{7}{8}\\ \dfrac{12}{5}:y=\dfrac{7}{8}:\dfrac{7}{4}\\ \dfrac{12}{5}:y=\dfrac{1}{2}\\ y=\dfrac{12}{5}:\dfrac{1}{2}=\dfrac{24}{5}\\ b,3\dfrac{2}{5}:y:1\dfrac{1}{4}=2\dfrac{3}{5}\\ \dfrac{17}{5}:y:\dfrac{5}{4}=\dfrac{13}{5}\\ y:\dfrac{5}{4}=\dfrac{17}{5}:\dfrac{13}{5}\\ y:\dfrac{5}{4}=\dfrac{17}{13}\\ y=\dfrac{17}{13}\times\dfrac{5}{4}=\dfrac{85}{52}\)
Đúng 2
Bình luận (0)
\(c,\dfrac{12}{5}-2\dfrac{2}{5}\times y=1\dfrac{1}{4}\\ \dfrac{12}{5}-\dfrac{12}{5}\times y=\dfrac{5}{4}\\ \dfrac{12}{5}\times y=\dfrac{12}{5}-\dfrac{5}{4}\\ \dfrac{12}{5}\times y=\dfrac{23}{20}\\ y=\dfrac{23}{20}:\dfrac{12}{5}\\ y=\dfrac{23}{48}\)
Đúng 2
Bình luận (0)
a, 2\(\dfrac{2}{5}\): y \(\times\)1\(\dfrac{3}{4}\) = \(\dfrac{7}{8}\)
\(\dfrac{12}{5}\) : y \(\times\dfrac{7}{4}\) = \(\dfrac{7}{8}\)
\(\dfrac{12}{5}\) : y = \(\dfrac{7}{8}\) : \(\dfrac{7}{4}\)
\(\dfrac{12}{5}\) : y = \(\dfrac{1}{2}\)
y = \(\dfrac{12}{5}\) : \(\dfrac{1}{2}\)
y = \(\dfrac{24}{5}\)
b, 3\(\dfrac{2}{5}\): y : 1\(\dfrac{1}{4}\) = 2\(\dfrac{3}{5}\)
\(\dfrac{17}{5}\): y: \(\dfrac{5}{4}\) = \(\dfrac{13}{5}\)
\(\dfrac{17}{5}\):y = \(\dfrac{13}{5}\times\dfrac{5}{4}\)
\(\dfrac{17}{5}\) : y = \(\dfrac{13}{4}\)
y = \(\dfrac{17}{5}\) : \(\dfrac{13}{4}\)
y = \(\dfrac{68}{65}\)
c, \(\dfrac{12}{5}\) - 2\(\dfrac{2}{5}\)\(\times y\) = 1\(\dfrac{1}{4}\)
\(\dfrac{12}{5}\) - \(\dfrac{12}{5}\)\(\times\)y = \(\dfrac{5}{4}\)
\(\dfrac{12}{5}\times y\) = \(\dfrac{12}{5}\) - \(\dfrac{5}{4}\)
\(\dfrac{12}{5}\) \(\times\) y = \(\dfrac{23}{20}\)
\(y\) = \(\dfrac{23}{20}\): \(\dfrac{12}{5}\)
y = \(\dfrac{23}{48}\)
Đúng 0
Bình luận (0)
Xem thêm câu trả lời
Giải các hệ phương trình sau:
c.{ 2(x - 2) + 3(1 + y) = 2
{ 3(x - 2) - 2(1 + y) = -3
d.{ (x - 5)(y - 2) = (x + 2)(y - 1)
{ (x - 4)(y + 7) = (x - 3)(y + 4)
e.{ 1/x - 1/y = 1
{ 3/x + 4/y = 5
e: \(\left\{{}\begin{matrix}\dfrac{1}{x}-\dfrac{1}{y}=1\\\dfrac{3}{x}+\dfrac{4}{y}=5\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\dfrac{3}{x}-\dfrac{3}{y}=3\\\dfrac{3}{x}+\dfrac{4}{y}=5\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{-7}{y}=-2\\\dfrac{1}{x}-\dfrac{1}{y}=1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=\dfrac{7}{2}\\\dfrac{1}{x}=1+\dfrac{2}{7}=\dfrac{9}{7}\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=\dfrac{7}{2}\\x=\dfrac{7}{9}\end{matrix}\right.\)
Đúng 1
Bình luận (0)
8/9 : ( 2 - 3 x y ) = 5/3
( 2 - 2/3 x y ) : 4 + 7/12 = 11/12
3 : ( 2 x y - 6/15 ) = 1 và 1/2 ( k biết ghi hỗn số nên ghi vậy cho dễ hiểu ạ )
2 - 1/5 x ( y : 7/2 + 1 ) = 1/2
2 và 3/5 x ( 5 : y ) - 3/4 = 0
7/12 : y + 4/9 x 5/8 = 0
4/15 + 2 : ( y + 2/5 ) = 1/5
\(\dfrac{8}{9}\) : ( 2 - 3 \(\times\) y) = \(\dfrac{5}{3}\)
2 - 3 \(\times\) y = \(\dfrac{8}{9}\) : \(\dfrac{5}{3}\)
2 - 3 \(\times\) y = \(\dfrac{8}{15}\)
3 \(\times\) y = 2 - \(\dfrac{8}{15}\)
3 \(\times\) y = \(\dfrac{22}{15}\)
y = \(\dfrac{22}{15}\) : 3
y = \(\dfrac{22}{45}\)
Đúng 0
Bình luận (0)
Đưa thừa số vào trong dấu căn:
c) 1/y√19yvới y >0 y d) 1 /3y√27/y2 y với y <0
Rút gọn biểu thức:
b) y/2+ 3/4 √1 -4y+ 4y2 với y< 1/2
. Thực hiện phép tính:
a)( 2/√3-1 +3/√3-2 +15/3-√3 )*1/√3+5
b,(√14-√7/1-√2 +√15-√5/1-√3)*1/√7 -√5
Bài 1:
c) \(\dfrac{1}{y}\sqrt{19y}=\sqrt{19y\cdot\dfrac{1}{y^2}}=\sqrt{\dfrac{19}{y}}\)
d) \(\dfrac{1}{3y}\cdot\sqrt{\dfrac{27}{y^2}}\cdot y=\sqrt{\dfrac{1}{9}\cdot\dfrac{27}{y^2}}=\sqrt{\dfrac{3}{y^2}}\)
Đúng 1
Bình luận (0)
Bài 3:
a) Ta có: \(\left(\dfrac{2}{\sqrt{3}-1}+\dfrac{3}{\sqrt{3}-2}+\dfrac{15}{3-\sqrt{3}}\right)\cdot\dfrac{1}{\sqrt{3}+5}\)
\(=\left(\dfrac{2\left(\sqrt{3}+1\right)}{2}-\dfrac{3\left(2+\sqrt{3}\right)}{1}+\dfrac{15\left(3+\sqrt{3}\right)}{6}\right)\cdot\dfrac{1}{\sqrt{3}+5}\)
\(=\left(\sqrt{3}+1-2-\sqrt{3}+\dfrac{5\left(3+\sqrt{3}\right)}{2}\right)\cdot\dfrac{1}{\sqrt{3}+5}\)
\(=\left(-1+\dfrac{5\left(3+\sqrt{3}\right)}{2}\right)\cdot\dfrac{1}{5+\sqrt{3}}\)
\(=\dfrac{-2+15+5\sqrt{3}}{2\left(5+\sqrt{3}\right)}\)
\(=\dfrac{13+5\sqrt{3}}{10+2\sqrt{3}}\)
Đúng 1
Bình luận (0)
1. x/y-2=3/2 và x-y=4
2. x-4/y+2=1/2 và x+y=5
3. 3/x-2=2/y+2 và x+y=5
4.3/x-2=2/y+2 và x+y=1
5.x+2/y+3=5/6 và x-y=1
6. x-1/y+4=3/4 và 2x=3y
7. x-1/y+4=3/4 và 2x=3y+2
vd câu 1:
ta có x-y=4 =>x=4+y
ta có pt:
4+y/y-2=3/2
=>8+2y=3y-6
=>-y=-14
=>y=14
=>x=4+y=4+14=18
các bài khác cũng tương tự thôi bạn
Đúng 0
Bình luận (0)
dấu chéo có nghĩa là phân số hí
Đúng 0
Bình luận (0)
Xem thêm câu trả lời