2/3 : 0.5 =
2/3 : 0.25=
3/8 : 0.5=
9/16 : 0.25=
0.25*2/1/3*30*0.5*8/45
\(0,25.2\frac{1}{3}.30.0,5.\frac{8}{45}\)
\(=\frac{1}{4}.\frac{7}{3}.30.\frac{1}{2}.\frac{8}{45}\)
\(=\frac{14}{9}\)
\(0,25.2\frac{1}{3}.30.0,5.\frac{8}{45}\)
\(=0,25.\frac{7}{3}.30.0,5.\frac{8}{45}\)
\(=\frac{7}{12}.30.\frac{4}{45}\)
\(\frac{35}{2}.\frac{4}{45}\)
\(=\frac{14}{9}\)
Tính nhanh:
\(25\%+\dfrac{3}{4}+\dfrac{1}{2}:0.5-\dfrac{1}{4}:0.25+\dfrac{1}{8}:0.125\)
`25%+3/4+1/2:0,5-1/4:0,15+1/8:0,125`
`=1/4+3/4+1/2xx2-1/4xx4+1/8xx8`
`(1/4+3/4)+(1/2xx2)-(1/4xx4)+(1/8xx8)`
`=1+1-1+1`
`=2`
2(x-0.5)+3=0.25(4x-1)
Bài làm:
\(2\left(x-0,5\right)+3=0,25\left(4x-1\right)\)
\(\Leftrightarrow2x-1+3=x-0,25\)
\(\Leftrightarrow2x-x=1-3-0,25\)
\(\Leftrightarrow x=-2,25\)
Vậy phương trình có tập nghiệm là \(S=\left\{-2,25\right\}\)
1. Giải các phương trình
b) 3+ (x-5)=2(3x-2) c) 2(x-0.5)+3=0.25(4x-1)
d) 2(x-\(\dfrac{1}{4}\))-4=-6(-\(\dfrac{1}{3}\)x+0.5)+2
b) Ta có: \(3+\left(x-5\right)=2\left(3x-2\right)\)
\(\Leftrightarrow3+x-5=6x-4\)
\(\Leftrightarrow x-2-6x+4=0\)
\(\Leftrightarrow-5x+2=0\)
\(\Leftrightarrow-5x=-2\)
\(\Leftrightarrow x=\dfrac{2}{5}\)
Vậy: \(S=\left\{\dfrac{2}{5}\right\}\)
c) Ta có: \(2\left(x-0.5\right)+3=0.25\left(4x-1\right)\)
\(\Leftrightarrow2x-1+3=x-\dfrac{1}{4}\)
\(\Leftrightarrow2x+2-x+\dfrac{1}{4}=0\)
\(\Leftrightarrow x+\dfrac{9}{4}=0\)
\(\Leftrightarrow x=-\dfrac{9}{4}\)
Vậy: \(S=\left\{-\dfrac{9}{4}\right\}\)
d) Ta có: \(2\left(x-\dfrac{1}{4}\right)-4=-6\left(-\dfrac{1}{3}x+0.5\right)+2\)
\(\Leftrightarrow2x-\dfrac{1}{2}-4=2x-3+2\)
\(\Leftrightarrow2x-\dfrac{9}{2}=2x-1\)
\(\Leftrightarrow2x-2x=-1+\dfrac{9}{2}\)
\(\Leftrightarrow0x=\dfrac{7}{2}\)(vô lý)
Vậy: \(S=\varnothing\)
b.
→ -2 + x = 6x - 4
→ -2 + 4 = 6x - x
→ 2 = 5x
→ x = \(\dfrac{2}{5}\)
Vậy, phương trình có tập nghiệm S = {\(\dfrac{2}{5}\)}
0.25 x 3/7 x30 x 0.5 x 8/45
Tinh gia tri bieu thuc : 170 + 9 + 6/100 + 3/10 ; tinh bang cach thuan tien : 1/2 : 0.5 - 1/4 : 0.25 + 1/8 : 0.125 - 1/10 : 0.1
tính diện tích mảnh đtất có hình dạng như hình vẽ dưới đây , biết :
BM=20,8m
CN=38m
AM=24,5m
MN=37,4m
ND=25,3m
2*4*8*0.5*0.125*0.25*(0.4321+0.5679)
x/0.5+x/0.25+x/0.1=16