[25(x+20) +75(x+18)] /100 = 35.5
Nguyễn thị kim oanh nè,bài của cậu đây.
Tính nhanh:
(75 x 625+175 x 625) : (20 x 25 x 125 - 625 x 75)
Cách làm:
(75 x 625+175 x 625) : (20 x 25 x 125 - 625 x 75)
=625 x (175+75) : (20 x 5 x 125 x 5 - 625 x 75)
=(625 x 250) : (20 x 5 x 625 - 625 x 75)
=(625 x 250 : (100 x 625 - 625 x 75)
=(625 x 250) : (625 x (100-75))
=(625 x 250) : (625 x 25)
=10
tính nhanh : 10 x 20 -100 x 75 + 10 x 80 - 100 x 25
kban vs mk nha
10 . 20 - 100 . 75 + 10 . 80 + 100 . 25
= 10 . ( 20 + 80 ) - 100 . ( 75 + 25 )
= 10 . 100 - 100 . 100
= 1000 - 10000
= - 9000
10 x 20 -100 x 75 + 10 x 80 - 100 x 25
10. 10. 2 - 100. 75 + 10. 10. 8 - 100 .25
100.2 -100.75 +100.8 - 100.25
200 - 7500 + 800 - 2500
vô lý
10x20-100x75+10x80-100x25
200-7500+800-2500
-9000
Tính nhanh :
75% + 18/21 + 19/32 + 25% + 3/21 + 13/32
35 x 11 x 0,1 x 0,25 x 100 x ( 3 : 0,4 - 7,5)
a: \(=\left(\dfrac{3}{4}+\dfrac{1}{4}\right)+\left(\dfrac{18}{21}+\dfrac{3}{21}\right)+\dfrac{19}{32}+\dfrac{13}{32}=1+1+1=3\)
b: \(=35\cdot1.1\cdot25\cdot\left(7,5-7,5\right)=0\)
25% : 75% = 33,33% = _________%
20% : 120% = 0,1% = _________%
130 : 90 x 100 = __________kg
25% : 75% = 33,33% = _________%
20% : 120% = 0,1% = _________%
130 : 90 x 100 = __________kg
mik cần gấp!!!
33,33%=10,415625
0,1%=0,03125
130 : 90 x 100 = 144,4444444444444
B1:Tính
a,3.52-16:22
b,22.17-23.14
c,15.141+59.10
d,17.85+15.17-120
e,100-[75-(7-2)]2
g,(23.94+93.45):(92.10-92)
B2:Tìm x
a,420+65.4=(x+175):3+30
b,96-3.(x+1)=42
c,(x-47)-115=0
d,(x-36):18=12
e,2x=16
B3:Tìm x
a,60-3.(x-2)=51
b,4x-20=25:22
c,8.6+288:(x-3)2=50
mk đang càn rất gấp
Bài 3:
a: Ta có: 60-3(x-2)=51
\(\Leftrightarrow x-2=3\)
hay x=5
b: Ta có: \(4x-20=25:2^2\)
\(\Leftrightarrow4x=\dfrac{25}{4}+20=\dfrac{105}{4}\)
hay \(x=\dfrac{105}{16}\)
c: Ta có: \(8\cdot6+288:\left(x-3\right)^2=50\)
\(\Leftrightarrow288:\left(x-3\right)^2=50-48=2\)
\(\Leftrightarrow\left(x-3\right)^2=144\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=12\\x-3=-12\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=15\\x=-9\end{matrix}\right.\)
tim X
a,( 25 * 12 - X - 25 ) : 25 = 4
b,180 - ( X + 15 ) : X * 20 = 100
c,125 + ( X - 25 ) * 5 + X = 150
d,X : 8 * 32 + X: 3 * 18 - X: 5 *10 = 120
d, X/8*32+X/3*18-X/5*10=120
X*32/8+X*18/3-X*10/5=120
32X/8+18X/3-10X/5=120
4X+6X-2X=120
8X=120
X=120/8
X=15
a, ( 25 * 12 - X - 25 ) : 25 = 4
( 25 * 12 - x - 25 ) = 4 * 25
( 25 * 12 - x - 25 ) = 100
300 - x - 25 = 100
300 - x = 100 + 25
300 - x = 125
x = 300 - 125
x = 175
Mẫu: 60 : 20 = ( 60 : 10 ) : ( 20 : 10 ) = 6 :2 = 3
A) 75 : 25 = ( 75 : ..... ) : ( 25 : 5 ) = ..........................................................
B) 90 : 18 = ( 90 : ..... ) : ( 18 : 9 ) = ..........................................................
A) 75 : 25 = ( 75 : 5 ) : ( 25 : 5 ) = 15 : 5 = 3
B) 90 : 18 = ( 90 : 18 ) : ( 18 : 18 ) = 5 : 1 = 5
A) vì hai số đều chia hết cho 5 cho nên lấy hai số chia 5 ra kết quả bao nhiêu thì lấy hai số đó chia cho nhau
B) vì hai số đều chia hết cho 18 cho nên lấy hai số chia 18 ra kêt quả bao nhiêu thì lấy hai số chia cho nhau
Tim x
A, 2x - ( x + 25 ) - 75 = -12
B, ( x - 12 ) - 15 = ( 120 - 18 ) - (20 + x )
C, 17 - { - x - [ - x - ( - x )] } = -16
D, x - { [ - x + ( x +3 ) ] - [ ( x +3) - ( x - 2) ] }= 0
a) \(2x-\left(x+25\right)-75=-12\)
\(\Rightarrow2x-\left(x+25\right)=63\)
\(\Rightarrow2x-x-25=63\)
\(\Rightarrow x=88\)
Vậy \(x=88\)
b) \(\left(x-12\right)-15=\left(120-18\right)-\left(20+x\right)\)
\(\Rightarrow\left(x-12\right)-15=102-20-x\)
\(\Rightarrow x-12-15=82-x\)
\(\Rightarrow x-27=82-x\)
\(\Rightarrow2x=27+82\)
\(\Rightarrow2x=109\)
\(\Rightarrow x=54,5\)
Vậy \(x=54,5\)
c) \(17-\left\{-x-\left[-x-\left(-x\right)\right]\right\}=-16\)
\(\Rightarrow17+x+x+x=-16\)
\(\Rightarrow17+3x=-16\)
\(\Rightarrow3x=-33\)
\(\Rightarrow x=-11\)
Vậy \(x=-11\)
d) \(x-\left\{\left[-x+\left(x+3\right)\right]-\left[\left(x+3\right)-\left(x-2\right)\right]\right\}=0\)
\(\Rightarrow x-\left\{\left[-x+x+3\right]-\left[x+3-x+2\right]\right\}=0\)
\(\Rightarrow x+2=0\)
\(\Rightarrow x=-2\)
Vậy \(x=-2\) (Câu này hơi tắt)