Chung minh cac phan so nay bang nhau:\(\frac{25}{53};\frac{2525}{5353};\frac{252525}{535353}\)
Ok!
B1)Tim X biet
A)3(X-4)-(8-X)=12
B)4(X-5)-(X=7)=-19
C)7(X-3)-5(3-X)=11X-5
B2)a)Chung to rang cac phan so tren bang nhau
A)25/53:2525/5353:252525/535353
B)37/41:3737/4141:373737/414141
b)Tim phan so bang phan so 11/33 va biet rang hieu cua mau va tu cua no bang 6
a) \(3\left(x-4\right)-\left(8-x\right)=12\)
\(3x-12-8+x=12\)
\(4x=12+12+8\)
\(4x=32\)
\(x=8\)
b) \(4\left(x-5\right)-\left(x-7\right)=-19\)
\(4x-20-x+7=-19\)
\(3x=-19+20-7\)
\(3x=-6\)
\(x=-2\)
c) \(7\left(x-3\right)-5\left(3-x\right)=11x-5\)
\(7\left(x-3\right)+5\left(x-3\right)=11x-5\)
\(\left(x-3\right).12=11x-5\)
\(12x-36-11x+5=0\)
\(x-31=0\)
\(x=31\)
a) \(\frac{25}{53}:\frac{2525}{5353}:\frac{252525}{535353}\)
rút gọn 2 phân số phía sau
\(\frac{2525}{5353}\) chia cả tử và mẫu cho \(101\)
\(\frac{252525}{535353}\)chia cả tử và mẫu cho \(10101\)
b) tương tự câu a) nhé
dung dinh nghia 2 phan thuc bang nhau chung minh cac phan thuc sau bang nhau
\(\frac{2-x}{2+x}=\frac{x^2-4x+4}{4-x^2}\)
\(\frac{x^3-9x}{15-5x}=\frac{-x^2-3x}{5}\)
Lời giải:
\(\frac{x^2-4x+4}{4-x^2}=\frac{x^2-2.2.x+2^2}{2^2-x^2}=\frac{(x-2)^2}{(2-x)(2+x)}=\frac{(2-x)^2}{(2-x)(2+x)}=\frac{2-x}{2+x}\) (đpcm)
\(\frac{x^3-9x}{15-5x}=\frac{x(x^2-9)}{5(3-x)}=\frac{x(x-3)(x+3)}{5(3-x)}=\frac{-x(3-x)(x+3)}{5(3-x)}=\frac{-x(x+3)}{5}=\frac{-x^2-3x}{5}\) (đpcm)
Cho phan so a/b co gia tri bang 3/4 neu giam mau so di 12 don vi va giu nguyen tu so thi duoc phan so moi co gia tri bang 6/7 tim gia tri cua phan so a/b
cho a/b bang 4/5 neu cong them 33 vao tu so va giu nguyen mau son thi duoc phan so moi la 25/41
ai nhanh minh tick
minh can gap chieu nay nop roi xin cac ban giup minh
A)Viet 5 phan so bé Hon 1,co Mau so la 7 va co tu so lon hon 0:
B)Viet 5 phan so lon hon 1 va co mau so la 5:
C)Viet 5 phan so bang phan so tam phan muoi hai :
D)Viet cac phan so khac 0 co tong cua tu so va mau so bang 7:
E)Hai phan so lon hon 1 co mau so bang 7 la :
G)Hai phan so bang 1 la:
H)Khoanh vao cac phan so bang ba muoi sau phan nam tu: Hai phan ba; sau phan muoi nam;tam phan muoi hai;muoi phan muoi nam
Giai ho minh bai toan nay nhe !Minh dang can bai toan nay trong ngay hom nay.
A LÀ 1/7,2/7,3/7,4/7,5/7
B LÀ 10/5,9/5,8/5,7/5,6/5
C LÀ 2/5,16/20,24/30,32/40,40/50
D LÀ 1/6,2/5,3/4,2/5/1/6
Ch0 em lam toan va tiêng viêt
Tim cac phan so bang nhau trong cac phan so sau Va giai thich vi sao chung bang nhau. 15/17, 28/42 , 1515/1717 , 65/117, 38/57 , 20/36
Tim ba phan so biet tong cua chung bang 3/3/70( hon so ) cac tu cua chung ti le voi 3;4;5; cac mau cua chung ti le voi 5;1;2.
Cac ban giai chi tiet gium minh nha , minh tick cho!!!!!!!!!
Cac ban giúp minh voi !!!!!!!!! Minh cam on nhiu!!!!!!!
Chtt ko co cau tra loi bn oi!!!! Neu bn biet thi giai chi tiet gium minh , minh tick cho nha Tuan !!!!!!!!
Khanh oi !!!! Ban dau roi ? Giai bai nay giúp minh voi!!!!!!!!!!!!
cho 25 so tu nhien lap nen tu 4 so ; 6,7,8,9 chung minh rang trong cac so do ta tim dc 2 so bang nhau
chung to cac phan so sau bang nhau:
7/9 = 77/99 = 777/999
Ta có : \(\frac{77}{99}=\frac{77:11}{99:11}=\frac{7}{9};\frac{777}{999}=\frac{777:111}{999:111}=\frac{7}{9}\)
Mà : \(\frac{7}{9}=\frac{7}{9}=\frac{7}{9}\)
Vậy : \(\frac{7}{9}=\frac{77}{99}=\frac{777}{999}\)
Ta tách : \(\frac{77}{99}=\frac{77:11}{99:11}=\frac{7}{9}\)
\(\frac{777}{999}=\frac{777:111}{999:111}=\frac{7}{9}\)
\(\Rightarrow\frac{77}{99}=\frac{777}{999}\)
cho 2 phan so 4/4 va 6/7 tu 2 phan so da cho lap 1 phan so thu ba bang cach ;tu so la tong cac tu so cua 2 phan so da cho ,mau so la tong cac mau so da cho.Hay so sanh ba phan so do voi nhau va xep chung theo thu tu tang dan