TÍnh nhanh
b. Q = 399x45+11x1995
3900x998-1991x1995
\(\frac{399x45+55x399}{1995x1996-1991x1995}\)
=\(\frac{399x\left(45+55\right)}{1995x\left(1996-1991\right)}\)
=\(\frac{399x100}{1995x5}\)
=\(\frac{399x4x5x5}{399x5x5}\)
=\(\frac{4}{1}\)
=\(4\)
= \(\frac{17955+21945}{3982020-3972045}\)
= \(\frac{39900}{9975}\)
= \(\frac{7980}{1995}\)
= \(\frac{1596}{399}\)
= \(\frac{532}{133}\)
Aswer : \(\frac{532}{133}\)
Tính nhanh:
\(\frac{399x45+55x399}{1995x1996-1991x1995}\)
ta tim xem hai ve deu co so nhan rieng la bao nieu roi ta tinh gia tri cua ve do roi tinh nhu thuong
Bài làm
\(\frac{399x\left(45+55\right)}{1995x\left(1996-1991\right)}\)
\(\frac{399x100}{1995x5}\)
\(\frac{399x5x5x4}{399x5x5}\)
\(\frac{4}{1}=4\)
Đáp số: 4
Chúc bạn học tốt
tính nhanh nhớ ghi cách làm
399x45+55x399
-----------------------
1995x1996-1991x1995
399 x 45 + 55 x399
= (45 + 55) x 399
= 100 x 399
= 39900
1995 x 1996 x 1995
= 1995 x ( 1996 - 1991 )
= 1995 x 5
= 9975
399x45+55x399/1995x1996-1991x1995
399x45+55x399/1995x1996-1991x1995
RÚt gọn nha
HELP ME :<
399x45+55x399/1995x1996-1991x1995
1994x1993-1992x1993/1992x1993+1994x7+1986
M.n giúp em nha !
399x45+55x399
1995x1996-1991x1995
1996x1995-399
1000+1996x1994
399 X 45 + 55 X 399 1995 X 1996 - 1991X 1995
= 399 X ( 45 + 55 ) = 1995 X ( 1996 - 1991 )
= 399 X 100 = 1995 X 5
= 39900 = 9975
1996 X 1995 - 399 1000 + 1996 X 1994
= 3982020 - 399 = 1000 + 3980024
= 3981621 = 3981024
A: 399x45+55x399
___________________
1995x1996-1991x1995
B:1996x1995-996
_______________
1000+1996x1994
Tính nhanh :
399x45 + 22x399
1995x1996 - 1991x1995
399x45+22x399
=399x(45+22)
=399x67
=26733
1995x1996-1991x1995
=1995x(1996-1991)
=1995x5
=9975
\(\frac{399\times45+22\times399}{1995×1996+1991×1995}=\frac{399\times(45+22)}{1995×\left(1996+1991\right)}=\frac{399\times67}{1995×3987}=\frac{67}{19935}\)