Tính nhanh:
\(\frac{1998\times1996+1997+1995}{1997\times1996-1995\times1996}\)
Tính nhanh \(\frac{1988\times1996+1997+1995}{1997\times1996-1995\times1996}\)
Tim A
\(A=\frac{1998\times1996+1997\times11+1985}{1997\times1996-1995\times1996}\)
\(A=\frac{1998.1996+1997.11+1985}{1997.1996-1995.1996}\)
\(A=\frac{1998.1996+\left(1996+1\right).11+1985}{1996.\left(1997-1995\right)}\)
\(A=\frac{1998.1996+1996.11+11+1985}{1996.2}\)
\(A=\frac{1998.1996+1996.11+1996}{1996.2}\)
\(A=\frac{1996.\left(1998+1+1\right)}{1996.2}\)
\(A=\frac{1996.2000}{1996.2}=1000\)
\(\frac{1998\times1996+1996\times11+1996}{1996\times2}\)\(=\frac{2010\times1996}{2\times1996}=1005\)
k nha
\(A=\frac{1998.1996+1997.11+1985}{1997.1996-1995.1996}\)
\(A=\frac{1998.1996+\left(1996+1\right).11+1985}{1996.\left(1997-1995\right)}\)
\(A=\frac{1998.1996+1996.11+11+1985}{1996.2}\)
\(A=\frac{1998.1996+1996.11+1996}{1996.2}\)
\(A=\frac{1996.\left(1998+1+1\right)}{1996.2}\)
\(A=\frac{1996.2000}{1996.2}=1000\)
Tính nhanh:
\(\dfrac{1988\times1996+1997+1985}{1997\times1996-1995\times1996}\)
\(\dfrac{1988\:×\:1996\:+\:1997\:+\:1985}{1997\:×\:1996\:-\:1995\:×\:1996}\) (rút bỏ các phần tử, mẫu giống nhau)
= \(\dfrac{1988\:+\:1985}{1995\:×\:1996}\)
= (còn lại tự tính)
Rút gọn phân số bằng cách hợp lí :
a) A = \(\frac{1988\times1996+1997+1985}{1997\times1996-1995\times1996}\)
b) B = \(\frac{1994\times1993-1992\times1993}{1992\times1993+1994\times7+1996}\)
Tính nhanh:
\((45\times46+47\times48)\times(51\times52-49\times48)\times(45\times128-90\times64)\times(1995\times1996+1997\times1998)\)
\(=\left(45\cdot128-45\cdot128\right)\cdot\left(45\cdot46+47\cdot48\right)\cdot\left(51\cdot52-49\cdot48\right)\cdot\left(1995\cdot1996+1997\cdot1998\right)\)
=0*A
=0
- Rút gọn phân số:
\(\frac{-1997\times1996+1}{-1995\times\left(-1997\right)+1996}\)
a/\(\frac{1988\times1996+1997+1985}{1997\times1996-1995\times1996}\)
b/\(\frac{1978\times1979+1980.21+1985}{1980\times1979-1978\times1979}\)
c/\(\frac{2,43\times12300-24,3\times1230}{45\times20,1+55\times28,9+4,5+3,3-55\times5,37}\)
Giúp mk nha, giải ra đầy đủ thì mk sẽ like :-)))
Rút gọn các phân số sau một cách hợp lí :
a) A = \(\frac{5^2.6^{11}.16^2+6^2.12^6.15^2}{2.6^{12}.10^4-81^2.960^3}\)
b) B = \(\frac{1988\times1996+1997+1985}{1997\times1996-1995\times1996}\)
c) C = \(\frac{1994\times1993-1992\times1993}{1992\times1993+1994\times7+1996}\)
\(\frac{-1997\times1996+1}{\left(-1995\right)\times\left(-1997\right)+1996}\)
Rút gọn phân số trên!
=1997 / -1995...tích mk nha mọi người...>0<
Cảm ơn nhưng mình tìm ra đáp án rồi :
\(\frac{-1997\times1996+1}{\left(-1995\right)\left(-1997\right)+1996}=\frac{-1997\times\left(1995+1\right)+1}{1995\times1997+1996}=\frac{-1997\times1995-1997+1}{1995\times1997+1996}=\frac{-1997\times1995-1996}{1995\times1997+1996}=\frac{-\left(1997\times1995+1996\right)}{1995\times1997+1996}=-1\)