\(2^3.\left(2,25-\dfrac{1}{4}\right):\left(\dfrac{10}{3}-1\dfrac{1}{3}\right)^2\\ =8.\left(\dfrac{9}{4}-\dfrac{1}{4}\right):\left(\dfrac{10}{3}-\dfrac{4}{3}\right)^2\\ =8.2:2^2\\ =16:4\\ =4\)
1. Tính hợp lí:
a) B = 1/2 - [ 3/8 + ( -7/4 ) ]
b) -4/12 - ( -13/39 - 0,25 ) + 0,75
c) 1/2 - 1/3 + 1/23 + 1/6
d) ( -13/7 - 4/9) - ( -10/7 - 4/9 )
e) ( 7/8 - 5/2 + 4/7 ) - ( -3/7 + 1 - 13/8 )
f) -3/7 + ( 3 - 3/4 ) - ( 2,25 - 10/7)
g) ( 5/3 - 3/7 + 9 ) - ( 2 + 5/7 - 2/3 ) + ( 8/7 - 4/3 - 10 )
-3/4 + (3-1/4) - (2,25 - 9/2)
B=(8-2,25+2/7)-(-6-3/7+1 1/4)-(3+0,5-1 2/7)
cứu zới
tìm x
a , ( 1/3 .x) : 2/3 = 1/3/4 : 2/5
b , 4,5 : 0,3 = 2,25 : ( 0,1 .x)
c , 8 : ( 1/4 .x ) = 2: 0,02
d , 3 : 2/1/4 = 3/4 : ( 6 .x )
1. tìm x trong các tỉ lệ thức sau:
a. \(\left(\frac{1}{3}.x\right):\frac{2}{3}=1\frac{3}{4}:2\)
b. 4,5:0,3 = 2,25:(0,1.x)
c. 8:\(\left(\frac{1}{4}.x\right)=2:0,02\)
c. \(3:2\frac{1}{4}=\frac{3}{4}:\left(6:x\right)\)
2. tìm hai số x,y,z biết rằng
\(\frac{x}{2}=\frac{y}{3},\frac{y}{4}=\frac{z}{5}\) và x+y-z=10
a, -1/5+x=2/3
b, (x-1/2)^3=-8
c, 2,25-|2x+1|=1,16
d, (2x-1)^2=4
\(\left(\dfrac{-2}{3}\right)^2.x=\left(\dfrac{-2}{3}\right)^5\)
\(\left(x-\dfrac{1}{2}\right)^3=\dfrac{1}{27}\)
\(\left(\dfrac{2}{3}x-1\right)\left(\dfrac{3}{4}x+\dfrac{1}{2}\right)=0\)
\(\dfrac{4}{9}:x=3\dfrac{1}{3}:2,25\)
\(1\dfrac{1}{3}:0,8=\dfrac{2}{3}:0,1x\)
a) 5√1,96 - 4√2,25 + 3√1,69
b) 1/3√49 + 3/4√324 - 2/3√400
c) 5/6√289 - 1/2√256 + 2/5√225
d) 15√16/25 + 12√9/16 - 18√16/81
tìm số tự nhiên x, biết:(1/1*2*3 1/2*3*4 ..... 1/8*9*10)*x=23/45
