Tìm y:
a) y-70=100
b) 80+y=180
c) 70-y=30
tìm y:
a, y x 27 + y x 30 + y x 44 - y = 10500
b, y x 285 + 115 x y = 400
\(a,y\times27+y\times30+y\times44-y=10500\\\Rightarrow y\times\left(27+30+44-1\right)=10500\\ \Rightarrow y\times100=10500\\ \Rightarrow y=10500:100\\ \Rightarrow y=105\\ b,y\times285+115\times y=400\\ \Rightarrow y\times\left(285+115\right)=40\\ \Rightarrow y\times400=400\\ y=400:400\\ \Rightarrow y=1\)
\(a,\Rightarrow y\times\left(27+30+44-1\right)=10500\\ \Rightarrow y\times100=10500\\ \Rightarrow y=105\\ b,\Rightarrow y\times\left(285+115\right)=400\\ \Rightarrow y\times400=400\\ \Rightarrow y=1\)
Tính nhẩm:
80 + 10 = 30 + 40 = 80 + 5 =
90 - 80 = 70 - 30 = 85 - 5 =
90 - 10 = 70 - 40 = 85 - 80 =
80 + 10 = 90 30 + 40 = 70 80 + 5 = 85
90 - 80 = 10 70 - 30 = 40 85 - 5 = 80
90 - 10 = 80 70 - 40 = 30 85 - 80 = 5
80+10=90 30+40=70 80+5=85
90-80=10 70-30=40 85-5=80
90-10=80 70-40=30 85-80=5
80 + 10 = 90 30 + 40 = 70 80 + 5 = 85
90 - 80 = 10 70 + 30 = 90 85 - 5 = 80
90 - 10 = 80 70 - 40 = 30 85 - 80 = 5
70/20+Y -30/Y=5/4
\(\frac{70}{20}+Y-\frac{30}{y}=\frac{5}{4}\)
\(Y\approx-6,71656731158626,\)
\(Y\approx4,46656731158626\)
Hk tốt
y-25-x=30+x biết y =70/x=21
y-25-x+30+x,biết x=70,y =21
21-25-70+30+70 =
{70+30}-{70+25-21}=100-74
=36
Tìm y:
a)y ×0,75= 1,8
b)0,15 ×y = 0,483
c)y –3,48 : 1,45 = 2,7
d)0,25 ×y –0,5 = 0,125
a) y=1,8:0,75=2,4
b) y=0,483:0,15=3,22
c) y=2,7+(3,48:1,45)=5,1
d) y=(0,125+0,5):0,25=0,7
Tìm y:
a)y x 7= 5,6% b)42% : y= 6
a: =>y=0,056:7=0,008
b: =>y=21/50:6=21/300=0,07
Tìm y:
a)y–(4,56 + 6,7) = 7,89
b) 45,32 –(y+ 12,34) = 17,65
Tìm y:
a) y x 4,5 = 55,8 b) y : 2,5 = 25,42
a)y=55,8 : 4,5
y=12,4
b) y=25,42 x 2,5
y= 63,55
`a)`
`yxx4,5=55,8`
`y=55,8:4,5`
`y=12,4`
`b)`
`y:2,5=25,42`
`y=25,42xx2,5`
`y=63,55`