tìm x,y biet1+3*y/12=1+5*y/5*x=1+7*y/4*x
Tìm y
\(\dfrac{2}{5}\) X y : \(\dfrac{7}{4}=\dfrac{7}{8}\)
2\(\dfrac{2}{5}\) : y x 1\(\dfrac{1}{4}\) = 2\(\dfrac{3}{5}\)
\(\dfrac{12}{5}-1\dfrac{2}{5}x\) y = 1\(\dfrac{1}{4}\)
\(\dfrac{2}{5}\) x y : \(\dfrac{7}{4}\) = \(\dfrac{7}{8}\)
\(\dfrac{2}{5}\) x y = \(\dfrac{7}{8}\) x \(\dfrac{7}{4}\)
\(\dfrac{2}{5}\) x y = \(\dfrac{49}{32}\)
y = \(\dfrac{49}{32}\) : \(\dfrac{2}{5}\)
y = \(\dfrac{245}{64}\)
2\(\dfrac{2}{5}\): y x 1\(\dfrac{1}{4}\) = 2\(\dfrac{3}{5}\)
\(\dfrac{12}{5}\): y x \(\dfrac{5}{4}\) = \(\dfrac{13}{5}\)
\(\dfrac{12}{5}\): y = \(\dfrac{13}{5}\): \(\dfrac{5}{4}\)
\(\dfrac{12}{5}\): y = \(\dfrac{52}{25}\)
y = \(\dfrac{12}{5}\): \(\dfrac{52}{25}\)
y = \(\dfrac{15}{13}\)
\(\dfrac{12}{5}\) - 1\(\dfrac{2}{5}\) \(\times\) y = 1\(\dfrac{1}{4}\)
\(\dfrac{12}{5}\) - \(\dfrac{7}{5}\) \(\times\) y = \(\dfrac{5}{4}\)
\(\dfrac{7}{5}\) \(\times\) y = \(\dfrac{12}{5}\) - \(\dfrac{5}{4}\)
\(\dfrac{7}{5}\) \(\times\) y = \(\dfrac{23}{20}\)
y = \(\dfrac{23}{20}\) : \(\dfrac{7}{5}\)
y = \(\dfrac{23}{28}\)
Tìm x, y ∈ Z biết.
a) (x + 1)(y – 2) = 0
b) (x – 5)(y – 7) = 1
c) (x + 4)(y – 2) = 2
d) (x + 3)(y – 6) = -4
e) (x + 7)(5 – y) = -6
f) (12 – x)(6 – y) = -2
tìm x,y thuộc Z biết:
a) 12/16=-x/4=21/y=Z/-80
b)5/12=x/-72
c)x+3/15=-1/3
d)3+x/7+y=3/7 và x+y=20
a: \(\Leftrightarrow\dfrac{x}{-4}=\dfrac{21}{y}=\dfrac{z}{-80}=\dfrac{3}{4}\)
=>x=-3; y=28; z=-60
b: 5/12=x/-72
=>x=-72*5/12=-6*5=-30
c: =>x+3=-5
=>x=-8
1.Tìm y
a, y x 4 7/12 = 6 1/4
b, y : 3 7/8 = 5 1/2
c, 6 1/7 : y = 5 2/5
( 2 x y + 2/15 ) x 3 = 4/5
7/9 x ( 2 - 1/3 x y ) = 14/15
4/21 + 5 x y - 8/7 = 1/3
7/12 x y - 3/12 x y = 5
6/7 x y + 14/36 + 1/7 x y = 7/18
Giúp em với ạ
( 2 x y + 2/15 ) x 3 = 4/5
( 2 x y + 2/15 ) = 4/5 : 3
( 2 x y + 2/15 ) = 4/15
2 x y = 4/15 - 2/15
2 x y = 2/15
y = 2/15 :2
y = 1/15
(2 x y + 2/15) x 3 = 4/5
2 x y + 2/15) = 4/5 : 3
2 x y + 2/15 = 4/15
2 x y = 4/15 - 2/15
2 x y = 2/15
y = 2/15 : 2
y = 1/15
7/9 x (2 - 1/3 x y) = 14/15
(2 - 1/3 x y) = 14/15 : 7/9
(2 - 1/3 x y) = 6/5
2 - y = 6/5 x 1/3
2 - y = 2/5
y = 2/5 + 2
y = 12/5
4/21 + 5 x y - 8/7 = 1/3
4/21 + 5 x y = 1/3 + 8/7
4/21 + 5 x y = 31/21
5 x y = 31/21 - 4/21
5 x y = 9/7
y = 9/7 : 5
y = 9/35
7/12 x y - 3/12 x y = 5
y x (7/12 - 3/12) = 5
y x 1/3 = 5
y = 5 : 1/3
y = 15
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 = \(\dfrac{22}{45}\)
bài 1: Tính
a} 5/12 + 1/3 x 3/5 =
B 7/5 - 4/9 : 2/5 =
C 2/5 x 1/4 : 2/5 =
bài 2: Tìm y
a 42/25 : y/5 = 5/6
b 27/y : 9/4 = 3/7
bài 2
a)42/25:y/5=5/6
y=10,08
b)27/y:9/4=3/7
y=28
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 \(=1\dfrac{1}{4}\)
\(a,2\dfrac{2}{5}:y\times1\dfrac{3}{4}=\dfrac{7}{8}\\ \dfrac{12}{5}:y\times\dfrac{7}{4}=\dfrac{7}{8}\\ \dfrac{12}{5}:y=\dfrac{7}{8}:\dfrac{7}{4}\\ \dfrac{12}{5}:y=\dfrac{1}{2}\\ y=\dfrac{12}{5}:\dfrac{1}{2}=\dfrac{24}{5}\\ b,3\dfrac{2}{5}:y:1\dfrac{1}{4}=2\dfrac{3}{5}\\ \dfrac{17}{5}:y:\dfrac{5}{4}=\dfrac{13}{5}\\ y:\dfrac{5}{4}=\dfrac{17}{5}:\dfrac{13}{5}\\ y:\dfrac{5}{4}=\dfrac{17}{13}\\ y=\dfrac{17}{13}\times\dfrac{5}{4}=\dfrac{85}{52}\)
\(c,\dfrac{12}{5}-2\dfrac{2}{5}\times y=1\dfrac{1}{4}\\ \dfrac{12}{5}-\dfrac{12}{5}\times y=\dfrac{5}{4}\\ \dfrac{12}{5}\times y=\dfrac{12}{5}-\dfrac{5}{4}\\ \dfrac{12}{5}\times y=\dfrac{23}{20}\\ y=\dfrac{23}{20}:\dfrac{12}{5}\\ y=\dfrac{23}{48}\)
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 = \(\dfrac{23}{48}\)
giải các hệ phương trình:
1, 2x+3|y-1|=5 và 3x+2y=7
2, |x+1|+|y-1|=5 và |x+1|-4y+4=0
3, (2x+1)/4-(y-3)/3=1/12 và (x+5)/2=(y+7)/3 -4
4, 1/x+1/y=1/12 và 8/x+15/y=1
5, 2/(x+2y) +1/(y+2x)=3 và 4/(x+2y) -3/(y+2x)=1