Tinh tong sau bang cach hop ly:
B = 5/2.1 + 4/1.11 + 3/11.2 + 1/2.15 + 13/15.4
Ghi ca cach lam nhe ! Ai nhanh nhat, dung nhat tick lun !!!!!!
Tinh hop ly tong sau
B= \(\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
\(B=\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
\(\Rightarrow\frac{B}{7}=\frac{5}{2.7}+\frac{4}{7.11}+\frac{3}{11.14}+\frac{1}{14.15}+\frac{13}{15.28}\)
\(\Rightarrow\frac{B}{7}=\frac{1}{2}-\frac{1}{7}+\frac{1}{7}-\frac{1}{11}+\frac{1}{11}-\frac{1}{14}+\frac{1}{14}-\frac{1}{15}+\frac{1}{15}-\frac{1}{28}\)
\(\Rightarrow\frac{B}{7}=\frac{1}{2}-\frac{1}{28}=\frac{13}{28}\)
\(\Rightarrow B=\frac{13}{28}.7=\frac{13}{4}\)
tinh nhanh
5/2.1+4/1.11+3/11.2+1/2.15+13/15.4
Tinh tong sau bang cach hop li nhat: (1+3+5+...+99)-(2+4+6+...+100)
Tim x va y thuoc Z, biet:
xy - x + 2y = 3 ghi cach lam nua nhe!
Ai nhanh nhat; dung nhat like lun!!!!!!
xy-x+2y=3
=y(x+2)-x=3
=y(x+2)-x+2=5
=(y+1)(x+2)=5
TH1
y+1=5=>y=4
x+2=1=>x=-1
TH2
y+1=1=>y=0
x+2=5=>x=3
TH3
y+1=-1=>y=-2
x+2=-5=>x=-7
TH4
y+1=-5=>y=-6
x+2=-1=>x=-3
k mình nha
<=>(x+2)y-x+y=3
=>(x+2)y-x-3=0
=>x+2=0
=>x=2
=>y-1=0
=>y=1
Nguyễn Trung Kiên giải sai rồi giải như Nguyễn Huy Thắng mới đúng
tim mot so tu nhien nho nhat thoa man voi dieu kien chia 5 du 4 ;chia 4 du 3
trinh bay cach tinh
ai lam dc tick nhe nhanh nhat co the
Tính nhanh
B=5/2.1+4/1.11+3/11.2+1/2.15+13/15.4
B = 7(5/2.7 + 4/7.11 + 3/11.14 + 1/14.15 + 13/15.28)
B = 7.(1/2 - 1/7 + 1/7 - 1/11 + 1/11 - 1/14 + 1/14 - 1/15 + 1/15 - 1/28)
B = 7.( 1/2 - 1/28)
B = 7. 13/28
B = 13/4
k mk đi!
=7.(5/2.7+4/7.11+3/11.14+1/14.15+13/15.28)
=7.(1/2-1/7+1/7-1/14+1/14-1/15+1/15-1/28)
=7.(1/2-1/28)
=13/4
tinh gia tri bieu thuc sau bang cach hop li:
B=1,3-3,2+5,1-7=8,9-10,8+ .... + 35,5 -37,4+39,3-41,2+43,1
minh tim ra cach lam rui nhung cac ban lam ho minh cach ngan gon nhat nhe
thanh nhieu
can thu nhat bang 40%can thu hai.nguoi ta do 3 lit cua can thu hai sang can thu nhat thi hai can bang nhau.tinh tong so lit cua 2 can luc dau.
cac bn ghi cach giai cho to,ai lam dung va nhanh nhat mk tick
Khong quy dong hay tinh:
B=5/2.1 + 4/ 1.11 + 3/ 11.2 + 1/ 2.15 + 13/ 15.4