1,25 x X + 3,75 x X =10
3 . tính bằng cách thuạn tiện nhất :
a. 23.4 : 25 : 0,4
b.1,25 + 2 x 1,25 + 1,25 x 3
c. 27,2 x 2,5 +2,5 x 72,8
d. 16,3 x 3,75 - 3,75 x 15,2
e . 2,5 x 7,36 x4
g. 1,25 x 6,54 x 8
g)1,25 x 6,54 x 8
=(1,25 x 8) x 6,54
=10 x 6,54
=65,4
5*x+3,75*x+1,25*x=20
5 *x + 3,75 *x + 1,25 *x= 20
<=>x* (5+3,75+1,25) =20
<=>x* 10 =20
<=>x = 20:10
<=>x =2
Timf y :
5 x y + 3,75 x y + 1,25 = 2
\(5\times y+3,75\times y+1,25=2\\ \Rightarrow\left(5+3,75\right)\times y=0,75\\ \Rightarrow8,75\times y=0,75\\ \Rightarrow y=\dfrac{3}{35}\)
5 x X + 3,75 x X + 1,25 x X = 20
giải hộ mik với các bạn ơi
5 x X + 3,75 x X + 1,25 x X = 20
X x (5+3,75+1,25) =20
X x 10 =20
X=20:10
X=2
5 x \(x\)+3,75 x \(x\)+1,25 x \(x\)=20
=> \(x\)x(5+3,75+1,25)=20
=>\(x\)x 10=20
=>x=20:10
=> x=2
vậy \(x\)=2
5 x X + 3,75 x X + 1,25 x X = 20
(5 + 3,75 + 1,25) x X = 20
10 x X = 20
X = 20 : 10
X = 2
3,75+1,25*x=4 và 3/4
32:(x:35)=5,6
giúp mình nhé
Tìm y
a) y x 3,75 + y x 1,25 = 120
b) y x 0,1 = 45,7 + 34,5
a) y x 3,75 + y x 1,25 = 120
( 3,75 + 1,25 ) x y = 120
5 x y = 120
y = 120 : 5
y = 24
b) y x 0,1 = 45,7 + 34,5
y x 0,1 = 80,2
y = 80,2 : 0,1
y = 802
a)=y*(3,75+1,25)=120
=y*5,05=120
y=120:5,05=
b)y*0,1=80,2
=80,2:0,1
Còn lại tự tính nhé
x × 0,9 = 4 - 0,022
4,27 - x = 13,5 : 45
x : 0,1 + x : 0,01 = 2,2
3,75 + 1,25 × x = 4 và 3/4
x.0,9 = 4-0,022
x.0,9= 3,978
x= 4,42
4,27 - x = 13,5 : 45
4,27 - x = 0,3
x = 3,97
x: 0,1 + x : 0,01 = 2,2
x : ( 0,1+ 0,01)=2,2
x : 0,11= 2,2
x = 0,242
x *0,9=3,978
x =3,978/0,9
x =4,42
4,27-x=13,5/45
4,27-x=0,3
x=4,27-0,3
x=3,97
x/0,1+x/0,01=2,2
x/0,11=2,2
x=2,2x0,11
x=0,242
3,75+1,25*x=4
1,25*x=4-3,75
1,25*x=0,25
x=0,25/1,25
x=0,2
3,75+1,25 *x=3/4
3,75+1,25*x=0,75
1,25*x=0,75-3,75
1,25*x=-3
x=-3/1,25
x=-2,4
x * 0,9 = 4 - 0,022
=> x * 0,9 = 3,978
=> x = 3,978 : 0,9
=> x = 4,42
4,27 - x = 13,5 : 45
=> 4,27 - x = 0,3
=> x = 4,27 - 0,3
=> x = 3,97
x : 0,1 + x : 0,01 = 2,2
=> x * 10 + x * 100 = 2,2
=> x * ( 10 + 100 ) = 2,2
=> x * 110 = 2,2
=> x = 2,2 : 110
=> x = 0,02
(1) 3,75 + 1,25 * x = 4
=> 1,25 * x = 4 - 3,75
=> x = 0,25 : 1,25
=> x = 0,2
(2) 3,75 + 1,25 * x = 3/4
=> 1,25 * x = 3/4 - 3,75
=> x = -3 : 1,25
=> x = -2,4
4,5 - 3,75 x 2 / 1,75 + 2,75 : 2 =a y - 3,75 x 2 / 1,25 + 2,75 : 2 = 2,5
Bài 1 tính nhanh ( đầy đủ ). ( dấu chấm là dấu nhân )
(84,6-2. x ):3,02=5,1
(15.24-x):0,25=100:0,25
128.x-12.x-16.x=5200
5.x+3,75.x+1,25.x=20
x.3,7+x.6,3=360:120
x.23-6.23+x.69=230
(x+1).(x+2)=72
(x+2).16.x=160.x
\(\left(84,6-2\cdot x\right):3,02=5,1\)
\(\Rightarrow84,6-2\cdot x=15,402\)
\(\Rightarrow2\cdot x=69,198\)
\(\Rightarrow x=69,198:2\)
\(\Rightarrow x=34,599\)
_____________
\(\left(15\cdot24-x\right):0,25=100:0,25\)
\(\Rightarrow\left(360-x\right):0,25=400\)
\(\Rightarrow360-x=100\)
\(\Rightarrow x-360-100\)
\(\Rightarrow x=260\)
______________
\(128\cdot x-12\cdot x-16\cdot x=5200\)
\(\Rightarrow x\cdot\left(128-12-16\right)=5200\)
\(\Rightarrow x\cdot100=5200\)
\(\Rightarrow x=5200:100\)
\(\Rightarrow x=52\)
__________________
\(5\cdot x+3,75\cdot x+1,25\cdot x=20\)
\(\Rightarrow x\cdot\left(5+3,75+1,25\right)=20\)
\(\Rightarrow10\cdot x=20\)
\(\Rightarrow x=20:10\)
\(\Rightarrow x=2\)
\(x\cdot3,7+x\cdot6,3=360:120\)
\(\Rightarrow x\cdot\left(3,7+6,3\right)=3\)
\(\Rightarrow x\cdot10=3\)
\(\Rightarrow x=\dfrac{3}{10}\)
__________________
\(x\cdot23-6\cdot23+x\cdot69=320\)
\(\Rightarrow x\cdot\left(23+69\right)=320+6\cdot23\)
\(\Rightarrow x\cdot92=458\)
\(\Rightarrow x=458:92\)
\(\Rightarrow x=\dfrac{229}{46}\)
___________________
\(\left(x+1\right)\left(x+2\right)=72\)
\(\Rightarrow x^2+2x+x+2=72\)
\(\Rightarrow x^2+3x+2=72\)
\(\Rightarrow x^2+3x+2-72=0\)
\(\Rightarrow x^2+3x-70=0\)
\(\Rightarrow x^2+10x-7x-70=0\)
\(\Rightarrow\left(x-7\right)\left(x+10\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=7\\x=-10\end{matrix}\right.\)
___________________
\(\left(x+2\right)\cdot16\cdot x=160x\)
\(\Rightarrow16x^2+32x=160x\)
\(\Rightarrow16x^2+32x-160x=0\)
\(\Rightarrow16x^2-128x=0\)
\(\Rightarrow16x\left(x-8\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x=8\end{matrix}\right.\)
Đổi:
f.x.23-6.23+x.69=230
=>23.(x-6+3x)=230
=>4x-6=10
=>4x=10+6
=>4x=16
=>x=4
h.(x+2).16.x=160.x
=>(16x+32).x = 160x
=>16x^2 + 32x = 160x
=>16x^2 = 128x
=>16x^2 - 128x=0
=>x(16x-128)=0
=>x=0 hoặc 16x-128=0
+)x=0=>x=0
+)16x-128=0
=>16x=128
=>x=8