áp dụng tính chất nhân cộng, tính nhanh.
(637 x 527 - 189) : (526 x 637 + 448)
Bài 3 : áp dụng các tính chất của phép cộng và phép nhân , tính nhanh :
a) (1989 x 1990 + 3978 ) : ( 1992 x 1991 - 3984 )
b ) ( 637 x 527 - 189 ) : ( 526 x 637 + 448 )
Giúp mình với ạ ! Mình đang cần gấp
Áp dụng tính chất của phép cộng và phép nhân ,tính nhanh:
a)(1 989 . 1 990 + 3 978) : (1 992 . 1 991 - 3 984)
b)(637 . 527 - 189) : (526 . 627 + 448)
tính nhanh : 637 nhân 527 - 189 / 526 nhân 637 + 448 (dấu / ngăn cách tử số và mẫu số)
\(\frac{637\times527-189}{526\times637+448}\)
\(=\frac{637\times526+527-189}{526\times637-189+637}\)
\(=\frac{1+527-189}{1-189+637}\)
\(=\frac{1-189+527}{1-189+637}\)
\(=\frac{527}{449}=\frac{339}{449}\)
~ Hok tốt ~
Tính nhanh 637*527-189 gach gang duoi 526*637+448
TÍNH NHANH
637 x 527 - 189
526 x 637 + 448
\(\frac{637\cdot526+637-189}{526\cdot637+448}\)=\(\frac{637\cdot526+448}{637\cdot526+448}\)=1
(637 x 527-189) : (526 x 637 +448)
\(\dfrac{637\times527-189}{526\times637+448}\)
\(=\dfrac{637\times\left(526+1\right)-189}{526\times637+448}\)
\(=\dfrac{637\times526+637-189}{526\times637+448}\)
\(=\dfrac{637\times526+448}{526\times637+448}\)
\(=\dfrac{1}{1}\)
\(=1\)
\(\dfrac{\left(637\cdot527-189\right)}{\left(526\cdot637+448\right)}\)
\(=\dfrac{\left(637\cdot526+637-189\right)}{\left(526\cdot637+448\right)}\)
\(=\dfrac{637\cdot526+448}{637\cdot526+448}=1\)
tính nhanh :
c) 637 x 527 - 189 / 526 x 637 + 448
d) 677 x 874 + 251 / 678 x 874 - 623
\(\frac{637\times527-189}{526\times637+448}\)
\(=\frac{637\times\left(526+1\right)-189}{526\times637+448}\)
\(=\frac{637\times526+637-189}{526\times637+448}\)
\(=\frac{637\times526+448}{526\times637+448}\)
\(=1\)
\(\frac{677\times874+251}{678\times874-623}\)
\(=\frac{677\times874+251}{\left(677+1\right)\times874-623}\)
\(=\frac{677\times874+251}{677\times874+874-623}\)
\(=\frac{677\times874+251}{677\times874+251}\)
\(=1\)
\(\frac{637\times527-189}{526\times637+448}\)
\(=\frac{526\times637+637-189}{526\times637+448}=\frac{526\times637+448}{526\times637+448}=1\)
tính nhanh :
c) 637 x 527 - 189 / 526 x 637 + 448
d) 677 x 874 + 251 / 678 x 874 - 623
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tính nhanh :
c) 637 x 527 - 189 / 526 x 637 + 448
d) 677 x 874 + 251 / 678 x 874 - 623
c) 637 x 527 - 189=335510 / 526 x 637 + 448=335510
d) 677 x 874 + 251 =591949 / 678 x 874 - 623=591949
học tốt
c, 637x527-189/526x637+448=335918,116
d, 677x874+251/678x874-623=91398,5605
\(\frac{677\times874+251}{678\times874-623}\)
\(=\frac{677\times874+251}{677\times874+874-623}=\frac{677\times874+251}{677\times874+251}\)
\(=1\)