Cau 1: Mot truong tieu hoc co 567 hoc sinh,so hoc sinh nam bang 2/3 so hoc sinh nu.Hoi truong do co bao nhieu hoc sinh nam,bao nhieu hoc sinh nu?
Cau 2: Mot thua ruong hinh chu nhat co chu vi la 350m,chieu rong bang 3/4 chieu dai.Tinh dien tich thua ruong hinh chu nhat do.
Cau 3: Ting gia tri cua bieu thuc:
a) (5/3 - 4/5) nhan 3/2 b) 3/2 + 3/4 : 2/3
Cau 4: Tinh bang cach thuan tien nhat.
a) 1/5 + 4/11 + 4/5 + 7/11 b) 27 nhan 45 - 23 nhan 27 - 27 nhan 11
đầu bài sai rồi
cau 1: giai
tong so phan bang nhau la:
2+3=5[phan]
truong do co so hoc sinh nam la:
567:5x2=226.8[hoc sinh]
so hoc sinh nu co trong truong la:
567-226.8=340.2[hoc sinh]
Dap so:226.8 hoc sinh nam
340.2 hoc sinh nu
cau 2: giai
nua chu vi hinh chu nhat do la:
350:2=175[m]
tong so phan bang nhau la:
3+4=7[phan]
chieu rong hinh thua ruong chu nhat do la:
175:7x3=75[m]
chieu dai hinh thua ruong chu nhat do la:
175-75=100[m]
dien h thua ruong do la:
100x75=7500[m2]
Dap so:7500m2
cau 3:tinh gia tri cua bieu thuc
a,[5/3-4/5]x3/2=[25/15-12/15]x3/2=13/15x3/2=39/30=13/10
b,3/2+3/4:2/3=3/2+9/6=3/2+3/2=6/2=3
cau 4:tinh bang cach thuan tien nhat:
a,1/5+4/11+4/5+7/11=[4/11+7/11]+[4/5+1/5]=1+1=2
b,27x45-23x27-27x11=27x[45-23-11]=27x11=297
o cau1,2 ban can them so do vao
o cau1 ban them ngay sau giai
o cau2 ban them so do sau khi tinh nua chu vi