mot don vi lam duong luc dau dat ke hoach giao cho 3 doi I, II, IIImoi doi lam 1 doan duong co chieu dai ti le (thuan )voi 7,8,9. nhung ve sau do thiet bi may moc va nhan luc cua doi thay doi nen ke hoach da duoc dieu chinh , moi doi lam mot doan duong ti le thuan voi 6,7,8. nhu vay doi IIIphai lam hon so voi ke hoach ban dau la 0,5 km duong . tinh chieu dai doan duong ma moi doi phai lam theo ke hoach moi
1.ba nha kinh doanh hun von theo ti le 2:3:4tinh so tien lai moi nguoi bik so tien lai dc chia theo ti le hun von tong so tien lai 180 trieu dong
2.bik cu 100kg thoc thi cho 60 kg gao. Hoi 20 bao thoc moi bao nang 60 kg thi cho bn kg gao ??
3.de dao con muong can 30 nguoi lm trog 8 h . neu tang them 10 thoi gian giam dc may h? (nang suat =nhau)
4. 2 xe o to tu A den B. van toc xe I la 60km/h. Van toc xe thu 2 la 40km/h. thoi gian xe I di it hon xe2 la 30 phut. Tinh thoi gian moi xe di tu A den B va chieu dai quang duong AB ?
5.ba doi may cay lm viec tren 3 canh dong co DT = nhau. Doi I hoan thanh cong viec trong 4 ngay, doi 2 trong 6 ngay , doi 3 trong 8 ngay. hoi moi doi co bn may( co cung nang suat)bik rang doi I nhieu hon doi 2 la 2 may?
6. cho ham so y=-2x
a. bik diem A(3:yo)thuoc dthi ham so y=-2x. tinh y mu 0
b. diemB(1,15:3) va C(1,5;-3) co thuoc dthi ham so y=-2x hay ko???
c.e do thi ham so y=-2x
3 doi san xuat duoc giao mot cong viec nhu nhau thoi gian hoan thanh cong viec cua doi 1 2 3 truong ung la 5 ngay 6 ngay 8 ngay biet nang suat lao dong cua moi cong nhan trong cac doi la nhu nhau tong so cong nhan 3 doi la 118 nguoi hoi moi doi co bao nhieu nguoi
Cho tam giac abc vuong tai a. Ke ah vuong goc voi bc tai h. Tren tia doi cua tia ha lay diem d sao cho ha=hd.
a) chung minh tam giac ahd=tam giac dhc
b)tren tia dc lay diem k sao cho c la trung diem cua dk. Chung minh ak||bc
c) tu c ke duong thang song song voi ab cat ak tai m. Doan thang bm cat ac tai q. Chung minh am+cm>2mq
nho thi dua 1 nha may da hoan thanh ke hoach ca nam khoi luong san ham thuc hioen cua 3 quy dau ti le voi 2/1/10,2/1/4,2/2/5 con quy 4 thuc hien duoc 28/100 ke hoch ca nam......hoi ca nam nha may san xuat bao nhieu tan hang hoa neu quy 3 nha may san xuat hon quy 1 là 48 tan
mot thua ruong hcn co 2 canh ti e voi 2va 5 biet chieu dai hon chieu rong la 24m tin h dien tich cu 5m2 thu hoach duoc 4 kg hoi thua ruong thu hoach dc bao nhieu kg
cho biet 2 dai luong x,y ti le nghich voi nhau va khi x=3 thi y=5
a,tim he so ti le b cua x doi voi y
b,hay bieu dien x theo y
c,tinh gia tri cua x khi y=-20;y=10
Nguoi ta tra thu lao cho 3 nguoi tho la 3.280.000 dong . Nguoi thu 1 lam duoc 96 cong cu , nguoi thu2 lam duoc 120 cong cu , nguoi thu 3 lam duoc 112 cong cu . Hoi moi nguoi nhan duoc bao nhieu tien ? Biet rang so tien duoc chia ti l voi so cong cu ma moi nguoi lam duoc.
cho tam giac ABC ,tren tia doi cua tia AB lay diem D.Tu D ke duong thang// BC cat tia AC tại E.Hai tia phan giac cua 2 goc AED va ABC cat nhau tai O.CMR:BOE=1/2(ABC+ACB)
cho tam giac abc nhon,2 duong cao BE va CF.tren tia doi cua BE lay M sao cho BM = AC.Tren tia doi cua CF lay N sao cho CN = AB.tinh so do goc AMN
