36/9:5/14+36/9:2/14
tính nhanh
Tính bằng cách thuận tiện:
a) 36 + 12 + 14 + 38
b) 2 x 3 x 5 000
c) 9 x 13 + 9 x 7
a) 36 + 12 + 14 + 38 = (36 + 14) + (12 + 38)
= 50 + 50
= 100
b) 2 x 3 x 5 000 = (2 x 5 000) x 3
= 10 000 x 3
= 30 000
c) 9 x 13 + 9 x 7 = 9 x (13 + 7)
= 9 x 20
= 180
36 mũ 10 . 14 . 126 / 35 mũ 5 . 6 ; 21 mũ 2 . 14 .126 / 35 mũ 5 .6 ; 4 mũ 9 . 36 + 64 mũ 4 / 100 . 16 mũ 4
36 mũ 10 . 14 . 126 / 35 mũ 5 . 6 ; 21 mũ 2 . 14 .126 / 35 mũ 5 .6 ; 4 mũ 9 . 36 + 64 mũ 4 / 100 . 16 mũ 4
\(\dfrac{4^9\cdot36+64^4}{100\cdot16^4}=\dfrac{2^{20}\cdot3^2+2^{24}}{2^{18}\cdot5^2}=\dfrac{2^{20}\left(3^2+2^4\right)}{2^{18}\cdot5^2}=4\)
Tính
5×36^9 ×4^6 -2 × 12^14 ×27^2
5×2^9 ×6^19 -7×2^29 ×17^6
giúp mình giải toán lớp 2 : Tính nhanh
a) 12+24+35-2-14-25
b) 1-2+3-4+5-6+7-8+9
c) 25-12-3+24+36
a)12+24+35-2-14-25=30
b)1-2+3-4+5-6+7-8+9=5
c)25-12-3+24+36=70
Tính nhanh
1, \(10\frac{5}{4}-4\frac{9}{14}-6\frac{5}{7}+\frac{7}{3}\)
2, \(\frac{29}{32}\left(\frac{41}{36}-\frac{32}{58}\right)-\frac{41}{36}\left(\frac{29}{32}+\frac{18}{41}\right)\)
Rút gọn rồi tính 5/15 + 48/16 6/9 : 12/36 4/12 × 56/14
\(\dfrac{5}{15}+\dfrac{48}{16}=\dfrac{1}{3}+3=\dfrac{1}{3}+\dfrac{9}{3}=\dfrac{10}{3}\)
\(\dfrac{6}{9}:\dfrac{12}{36}=\dfrac{2}{3}:\dfrac{1}{3}=\dfrac{2}{3}\times\dfrac{3}{1}=\dfrac{6}{3}=2\)
\(\dfrac{4}{12}\times\dfrac{56}{14}=\dfrac{1}{3}\times4=\dfrac{4}{3}\)
Tính nhanh:
a,1/4+2/5+6/8+9/15+8/1
b,1/2+2/4+3/6+4/8+5/10+6/12+7/14+8/16+9/18+10/20
c,1/10+4/20+9/30+16/40+25/50+36/60+49/70+64/80+81/90
a; \(\dfrac{1}{4}\) + \(\dfrac{2}{5}\) + \(\dfrac{6}{8}\) + \(\dfrac{9}{15}\) + \(\dfrac{8}{1}\)
= (\(\dfrac{1}{4}\) + \(\dfrac{6}{8}\)) + (\(\dfrac{2}{5}\) + \(\dfrac{9}{15}\)) + \(\dfrac{8}{1}\)
= (\(\dfrac{1}{4}\) + \(\dfrac{3}{4}\)) + (\(\dfrac{2}{5}\) + \(\dfrac{3}{5}\)) + 8
= 1 + 1 + 8
= 2 + 8
= 10
b; \(\dfrac{1}{2}\) + \(\dfrac{2}{4}\) + \(\dfrac{3}{6}\) + \(\dfrac{4}{8}\) + \(\dfrac{5}{10}\) + \(\dfrac{6}{12}\) + \(\dfrac{7}{14}\) + \(\dfrac{8}{16}\) + \(\dfrac{10}{20}\)
= \(\dfrac{1}{2}\) + \(\dfrac{1}{2}\) x (\(\dfrac{2}{2}\) + \(\dfrac{3}{3}\) + \(\dfrac{4}{4}\) + \(\dfrac{5}{5}\)+ \(\dfrac{6}{6}+\dfrac{7}{7}+\dfrac{8}{8}\) + \(\dfrac{10}{10}\))
= \(\dfrac{1}{2}\) + \(\dfrac{1}{2}\) x (1 + 1 +1 + 1+ 1+ 1+ 1 +1)
= \(\dfrac{1}{2}\) + \(\dfrac{1}{2}\) x 1 x 8
= \(\dfrac{1}{2}\) + \(\)\(\dfrac{1}{2}\) x 8
= \(\dfrac{1}{2}\) + 4
= \(\dfrac{9}{2}\)
c; \(\dfrac{1}{10}\) + \(\dfrac{4}{20}\) + \(\dfrac{9}{30}\)+\(\dfrac{16}{40}+\dfrac{25}{50}+\dfrac{36}{60}+\dfrac{49}{70}+\dfrac{64}{80}+\dfrac{81}{90}\)
= \(\dfrac{1}{10}+\dfrac{2}{10}+\dfrac{3}{10}+\dfrac{4}{10}+\dfrac{5}{10}+\dfrac{6}{10}+\dfrac{7}{10}+\dfrac{8}{10}+\dfrac{9}{10}\)
= \(\dfrac{1+2+3+4+5+6+7+8+9}{10}\)
= \(\dfrac{\left(1+9\right)+\left(2+8\right)+\left(3+7\right)+\left(4+6\right)+5}{10}\)
= \(\dfrac{10+10+10+10+5}{10}\)
= \(\dfrac{\left(10+10+10+10\right)+5}{10}\)
= \(\dfrac{10\times4+5}{10}\)
= \(\dfrac{45}{10}\)
= \(\dfrac{9}{2}\)