tinh nhanh
A = ( 7 - 3/4 + 1/3) - ( -6 + 5/4 - 4/3) -( 13 - 7/4 + 5/3)
BAI 1 : TINH NHANH BANG CACH THUAN TIEN NHAT :
A} 13/4 + 7/12 + 3/4 + 17/12
B} 1 VA 2/3 + 4 VA 4/7 + 5 VA 1/3 + 6 VA 3/7
C} 3/4 * 7/9 = 3/4 * 2/9
D} 3/4 * 4/5 * 5/6
BAI 3 : TINH
A} 3/4 CUA 16 KG .....
B} 7/12 CUA 840 M .....
C} 13/15 CUA 135 M3 .....
D} 6/7 CUA 280 L......
8)Tính nhanh :
a) -3/7+5/13+ -4/7
b)-5/8+3/4+ -1/5+-3/8+1/4
c)6/7.8/13+6/7.9/13+ -3/13.6/7
d)-5/7.2/11+ -5/7.9/11+1 5/7
e)11 3/13 - (2 4/7+5 3/13)
f) (1-1/2)(1-1/3)(1-1/4)(1-1/5)
tính nhanh
a,(-3/4 + 5/13):2/7-(2/1/2+8/13):2/7
b,-3/5:(-1/15-1/6)+3/5:(-1/3-1/1/15)
c,(3-1/4+2/3)-(5-1/3-6/5)-(6-7/4+3/2)
A) (-3/4 + 5/13):2/7-(2/1/2+8/13):2/7
\(=\)
\(=\)
B) -3/5:(-1/15-1/6)+3/5:(-1/3-1/1/15)
\(=\)
\(=\)
tính nhanh
a,(-3/4 + 5/13):2/7-(2/1/2+8/13):2/7
b,-3/5:(-1/15-1/6)+3/5:(-1/3-1/1/15)
c,(3-1/4+2/3)-(5-1/3-6/5)-(6-7/4+3/2)
tính nhanh
a,(-3/4 + 5/13):2/7-(2/1/2+8/13):2/7
b,-3/5:(-1/15-1/6)+3/5:(-1/3-1/1/15)
c,(3-1/4+2/3)-(5-1/3-6/5)-(6-7/4+3/2)
a: \(=\left(-\dfrac{3}{4}+\dfrac{5}{13}\right)\cdot\dfrac{7}{2}-\left(\dfrac{5}{2}+\dfrac{8}{13}\right)\cdot\dfrac{7}{2}\)
\(=\dfrac{7}{2}\left(-\dfrac{3}{4}+\dfrac{5}{13}-\dfrac{5}{3}-\dfrac{8}{13}\right)\)
\(=\dfrac{7}{2}\cdot\dfrac{-413}{156}=\dfrac{-2891}{312}\)
b: \(=-\dfrac{3}{5}:\left(\dfrac{-2-5}{30}\right)+\dfrac{3}{5}:\left(-\dfrac{1}{3}-\dfrac{16}{15}\right)\)
\(=\dfrac{-3}{5}\cdot\dfrac{-30}{7}+\dfrac{3}{5}:\dfrac{-5-16}{15}\)
\(=\dfrac{3}{5}\cdot\dfrac{30}{7}+\dfrac{3}{5}\cdot\dfrac{-5}{7}\)
\(=\dfrac{3}{5}\cdot\dfrac{25}{7}=\dfrac{15}{7}\)
c: \(=3-\dfrac{1}{4}+\dfrac{2}{3}-5+\dfrac{1}{3}+\dfrac{6}{5}-6+\dfrac{7}{4}-\dfrac{3}{2}\)
\(=\left(3-5-6\right)+\left(\dfrac{-1}{4}+\dfrac{7}{4}-\dfrac{3}{2}\right)+\left(\dfrac{2}{3}+\dfrac{1}{3}\right)+\dfrac{6}{5}\)
\(=-8+1+\dfrac{6}{5}=-7+\dfrac{6}{5}=\dfrac{-35+6}{5}=\dfrac{-29}{5}\)
tính nhanh
a,(-3/4 + 5/13):2/7-(2/1/2+8/13):2/7
b,-3/5:(-1/15-1/6)+3/5:(-1/3-1/1/15)
c,(3-1/4+2/3)-(5-1/3-6/5)-(6-7/4+3/2)
thanks nha
tính nhanh
a,(-3/4 + 5/13):2/7-(2/1/2+8/13):2/7
b,-3/5:(-1/15-1/6)+3/5:(-1/3-1/1/15)
c,(3-1/4+2/3)-(5-1/3-6/5)-(6-7/4+3/2)
Bài 1 Tính nhanh
a) -3/7 + 5/13 + 3/7
b) -5/21+-2/21+8/24
c) -5/11+(-6/11+2)
d) (-1/32+1/2)+15/32
e)5/17+ -6/13 + 3/4 + 7/-13+12/17
f) 7/23+-18/18+-4/9+16/23+-5/8
g)1/3+-3/4+3/5+-1/36+1/15+-2/9
h)-1/2+1/3+-1/4+-2/8+4/18+4/9
a)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\)
=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\)
=\(0+\dfrac{5}{13}\)
=\(\dfrac{5}{13}\)
Tinh A
(3/7-3/13+3/37)/(5/7-5/13+5/37)+(1/2-1/3+1/4-1/5)/(7/5-7/4+7/3-7/2)