x + 24 /28 = 15/14
Nối hai phân số bằng nhau:
3/4 3/7 1và5/7 20/28
24/14 15/20 5/7 15/32
Rút gọn các phân số sau
a ) 4 12 ; b ) 15 60 ; c ) − 4 12
d ) − 14 − 28 ; e ) 35 140 ; f ) − 15 − 25
g ) − 16 − 24 ; h ) 42 − 28
a ) 1 3 b ) 1 4 c ) − 1 3
d ) 1 2 e ) 1 4 f ) 3 5
g ) 2 3 h ) − 3 2
Tính nhanh:24 x 14 x 30 / 28 x 12 x 60,lưu ý ở chỗ 30/28 ko phải là 30 phần 28
\(\frac{24\times14\times30}{28\times12\times60}\)
\(=\frac{24}{12}\times\frac{28}{14}\times\frac{60}{30}\)
\(=2\times2\times2\)
\(=8\)
À phần của mik tính tiếp:mik quên rút gọn. Đáp án thật là 1/2
Mik muốn thêm vài câu hỏi nữa . Mọi người giúp mik nha !
284 : [ 314 - (x+3)]=12
14.[251 - (x-5)]=1470
(120 + x) : x - 15 = 16
(135 - x) : x + 24 = 28
Thanks mn nha
\(284:\left[314-\left(x+3\right)\right]=12.\)
\(\Leftrightarrow\left[314-\left(x+3\right)\right]=\frac{71}{3}\)
\(\Leftrightarrow\left(x+3\right)=\frac{871}{3}\)
\(\Leftrightarrow x=\frac{862}{3}\)
\(14.\left[251-\left(x-5\right)\right]=1470\)
\(\Leftrightarrow\left[251-\left(x-5\right)\right]=105\)
\(\Leftrightarrow x-5=146\)
\(\Leftrightarrow x=151\)
\(\left(120+x\right):x-15=16\)
\(\Leftrightarrow\left(120+x\right):x=31\)
\(\Leftrightarrow\left(120+x\right).\frac{1}{x}=31\)
\(\Leftrightarrow\frac{1}{x}.x+120x=31\)
\(\Leftrightarrow1+120x=31\)
\(\Leftrightarrow120x=30\)
\(\Leftrightarrow x=4\)
\(\left(135-x\right):x+24=28\)
\(\Leftrightarrow\left(135-x\right):x=4\)
\(\Leftrightarrow\left(135-x\right).\frac{1}{x}=4\)
\(\Leftrightarrow\frac{1}{x}.135-\frac{1}{x}x=4\)
\(\Leftrightarrow\frac{1}{x}135-1=4\)
\(\Leftrightarrow\frac{1}{x}135=5\)
\(\Leftrightarrow\frac{1}{x}=\frac{1}{27}\)
\(\Leftrightarrow x=27\)
a,2.(x-5)-3.(x+7)=14
b,5.(x-6)-2.(x+3)=12
c,-5.(2-x)+4.(x-3)=10.x-15
d,-7.(3x-5)+2.(7.x-14)=28
e,5.(4-x)-7.(-x+2)=4-9+3
f,-4.(2.x+1)+8.(3-2.x)=24
1.Tính nhanh:
a) 9-10+11-12+13-14+15
b)22+24+26-28+30
a) (9+11+13+15)-(10+12+14)
= 38 - 36
= 2
b) (22+26-28)+(24+30)
= 20 +54
= 74
k cho mik nha
a ) 9 - 10 + 11 - 12 + 13 - 14 + 15
= ( 9 - 10 ) + ( 11 - 12 ) + ( 13 - 14 ) + 15
= ( - 1 ) + ( -1 ) + ( - 1 ) + 15
= ( - 3 ) + 15
= 12
b ) 22 + 24 + 26 - 28 + 30
= 22 + ( 24 + 26 ) + ( 30 - 28 )
= 22 + 50 + 2
= 24 + 50
= 74
Tìm x
a) x – 12 = 14
b) 2x – 13 = 3.17
c) x – 43 = 2.18
d) (x – 14).39 = 0
e) (13 – x).28 = 28
f) 22.(35 – x) = 22
g) x – 24 : 2 = 18
h) 400 + (275 – x) = 570
a) x – 12 = 14
x = 14 +12
x = 26
b) 2x – 13 = 3.17
2x = 51 + 13
2x = 64
x = 64 : 2
x = 32
c) x – 43 = 2.18
x = 36 +43
x = 79
d) (x – 14).39 = 0
x – 14 = 0
x = 14
e) (13 – x).28 = 28
13 – x = 1
13 – x = 1
x = 13 – 1
x = 12
f) 22.(35 – x) = 22
35 – x = 1
x = 35 – 1
x = 34
g) x – 24 : 2 = 18
x – 12 = 18
x = 39
h) 400 + (275 – x) = 570
275 – x = 570 – 400
275 – x = 170
x = 275 – 170
x = 105
tim cac phan so bang nhautrong cac phan so day :2:5 ; 4:7; 6:15; 8:14; 16:28; 24:60;
-8.4+19=
-11.3-28=
4.(-15)-18=
19-4.(-12)=
-25.(-3)-54=
-16-7.(-4)+24:(-8)=
15:(-3)+30-7.(-3)=
-48:(-4)+12.(-5)=
-29+65:(-5)+23=
15:(-5)-17-12.(-5)=
28.(-4)-17=
-19-7.4=
-14.(-2)-16=
13.(-3)-65-4.(-6)=
-24-8.(-6)+28=
\(-8.4+19=-32+19=-13\)
\(-11.3-28=-33-28=-61\)
\(4.\left(-15\right)-18=-60-18=-78\)
\(19-4.\left(-12\right)=19+48=67\)
\(-25.\left(-3\right)-54=75-54=21\)
\(-16-7.\left(-4\right)+24\div\left(-8\right)=-16+28-3=9\)
\(15\div\left(-3\right)+30-7.\left(-3\right)=-5+30+21=46\)
\(-48\div\left(-4\right)+15.\left(-5\right)=12-75=-63\)
\(-29+65\div\left(-5\right)+23=-29-13+23=-19\)
\(15\div\left(-5\right)-17-12.\left(-5\right)=-3-17+60=40\)
\(28.\left(-4\right)-17=-112-17=-129\)
\(-19-7.4=-19-28=-47\)
\(-14.\left(-2\right)-16=28-16=12\)
\(13.\left(-3\right)-65-4.\left(-6\right)=-39-65+24=-80\)
\(-24-8.\left(-6\right)+28=-24+48+28=52\)
Chúc bạn hok tốt!!! tỷ tỷ