bài 4.Tìm y
a) 42 : y = 56 : 8 b) y : 6 + 25 = 83 c) y : 4 = 32 ( dư 3 )
d) y : 7 - 45 = 18 e) 42 : y = 5 ( dư 2 ) g) 51 : y = 6 ( dư 3 )
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(a,\frac{42}{25}:\frac{y}{5}=\frac{6}{5}\)
\(\frac{y}{5}=\frac{42}{25}:\frac{6}{5}\)
\(\frac{y}{5}=\frac{42}{25}\times\frac{5}{6}\)
\(\frac{y}{5}=\frac{7}{5}\)
\(\Leftrightarrow5y=7.5\)
\(5y=35\)
\(y=7\)
1: Áp dụng tính chất của DTSBN, ta được:
\(\dfrac{x}{7}=\dfrac{y}{13}=\dfrac{x-y}{7-13}=\dfrac{42}{-6}=-7\)
=>x=-48; y=-91
2: x/y=3/4
=>4x=3y
=>4x-3y=0
mà 2x+y=10
nên x=3 và y=4
3: =>7x-3y=0 và x-y=-24
=>x=18 và y=42
4: =>7x-5y=0 và x+y=24
=>x=10 và y=14
a) y = \(\frac{4}{5}-\frac{3}{4}\)
\(\Rightarrow y=\frac{16}{20}-\frac{15}{20}\)
\(\Rightarrow y=\frac{1}{20}\)
b)\(\frac{y}{7}=\frac{7}{8}-\frac{25}{26}\)
\(\Rightarrow\frac{y}{7}=-\frac{9}{104}\)
\(\Rightarrow y=\frac{-9}{104}.7\)
\(\Rightarrow y=\frac{-63}{104}\)
c) y \(+\frac{7}{12}=\frac{17}{18}-\frac{1}{9}\)
\(\Rightarrow y+\frac{7}{12}=\frac{15}{18}=\frac{5}{6}\)
\(\Rightarrow y=\frac{5}{6}-\frac{7}{12}\)
\(\Rightarrow y=\frac{3}{12}=\frac{1}{4}\)
d)\(y=\frac{7}{8}:\frac{3}{5}=\frac{7}{8}.\frac{5}{3}=\frac{35}{24}\)
e)\(y:4,5=\frac{1}{2}:\frac{6}{5}\)
\(\Rightarrow y:\frac{9}{2}=\frac{1}{2}.\frac{5}{6}=\frac{5}{12}\)
\(\Rightarrow y=\frac{5}{12}.\frac{9}{2}=\frac{15}{8}\)
a) => y+42+2y= -12-14+2y
y+2y-2y = -12-14-42
y= -68
b) => 15+y-5-5y= -12-5y
y-5y+5y= -12-15+5
y = -22
c) => 2y+5-8y+21= -3-5y-2
2y-8y+5y= -3-2-5-21
-y= -31=>y=31
d)=> -13+3y+23= -120+y
3y-y= -120+13-23
2y= -130=>y= -65
e) => -21+32+5y= 16+4y
5y-4y= 16+21-32
y= 5
bài 1
a)y-(-42-2y) = (-12) - 14 +2y
y +42 + 2y = -12 -14 +2y
3y + 42 = -26 +2y
y = -68
b)15-(-y+5)-5y=-(12+5y+2)
15+y-5-5y=-12-5y-2
10-4y=-14-5y
-4y+5y=-14-10=-24
c)2y-(-5+8y-21)=-3-(5y+2)
2y+5-8y+21=-3y-5y-2
-6y+26=-8y-2
-6y+8y=-2-26
2y=-28
y=-28/2=-14
a)100-9:(372:3.y-1)-14=83
<=>100-9:(124y-1)-14=83
<=>86-9:(124y-1)=83
<=>9:(124y-1)=3
<=>124y-1=3
<=>124y=4
<=>y=\(\frac{1}{31}\approx0,3223\)
b)7260-120:24.y+924=528,3
<=>8184-5y=528,3
<=>5y=7655,7
<=>y=1531,14
c)2000-52:(615:3:y-15)-14=1984
<=>1986-52:(205:y-15)=1984
<=>52:(205:y-15)=2
<=>205:y-15=26
<=>205:y=41
<=>y=5
d)y+y.1/3+5/18=7/18
<=>4/3y=1/9
<=>y=1/12
e)13/15-(5/21+y)7/12=7/10
<=>7/12.(5/21+y)=1/6
<=>5/36+7/12y=1/6
<=>7/12y=1/36
<=>y=1/21\(\approx\)0,4762
h)y+2.y+3.y+...+10.y=49,5
<=>55y=49,5
<=>y=0,9
i)y.(1975/8.9+1885/9.10+1755/10.11+1579/11.12)=1/24
<=>7991,364899y=1/24
<=>y=33/6329161
tích nha mỏi tay quá
a) 42:y=56:8 b) y:6+25=83 c) y:4=32(dư 3) d) y:7-45=18 e) 42:y=5(dư 2) g) 51:y=6(dư 3)
42:y=7 y:6=83-25 y=32*4+3 y:7=18+45 y=(42-2):5 y=(51-3):6
y=42:7 y:6=58 y=128+3 y:7=63 y=40:5 y=48:6
y=6 y=58*6 y=131 y=63*7 y=8 y=8
y=348 y=441