Tính :
a) \(\left(-16\right).12\)
b) \(22.\left(-5\right)\)
c) \(\left(-2500\right).\left(-100\right)\)
d) \(\left(-11\right)^2\)
Tính một cách hợp lí:
a) \(\left(-16\right).\left(-7\right).5;\) b) \(11.\left(-12\right)+11.\left(-18\right);\)
c) \(87.\left(-19\right)-37.\left(-19\right);\) d) \(41.81.\left(-451\right).0.\)
a) (- 16) . (- 7) . 5 = [(- 16) . 5] . (- 7) = 560.
b) 11 . (- 12) + 11 . (- 18) = 11 . [(- 12) + (- 18)] = 11 . [- (12 + 18)] = 11 . (- 30) = - 330.
c) 87 . (- 19) – 37 . (- 19) = (- 19) . (87 – 37) = (- 19) . 50 = - 950.
d) 41 . 81 . (- 451) . 0 = 0.
a) (- 16) . (- 7) . 5 = [(- 16) . 5] . (- 7) = 560.
b) 11 . (- 12) + 11 . (- 18) = 11 . [(- 12) + (- 18)] = 11 . [- (12 + 18)] = 11 . (- 30) = - 330.
c) 87 . (- 19) – 37 . (- 19) = (- 19) . (87 – 37) = (- 19) . 50 = - 950.
d) 41 . 81 . (- 451) . 0 = 0.
a) (-16).(-7).5
=16.7.5 = 2.8.7.5
=(2.5).(8.7) = 56 . 10 =560
b) 11 . (-12) + 11.(-18)
=11 . (-12 -18)
=11.(-20) = -220
c) 87.(-19) - 37 .(-19)
=(-87).19 + 37.19
=19 . (-87+37)
=19.(-50)
= -950
d) 41.81.(-451).0
= (mọi số nhân 0 đều bằng 0)
\(c)160:\left\{17+[3^2\times5-\left(14+2^{11}:2^8\right)]\right\}\)
\(d)798+100:[16-2\times\left(5^2-22\right)]\)
c
\(=160:\left\{17+\left[9\cdot5-\left(14+2^3\right)\right]\right\}\)
\(=160:\left\{17+\left[45-\left(14+8\right)\right]\right\}\)
\(=160:\left\{17+\left[45-22\right]\right\}\)
\(=160:\left(17+23\right)\)
\(=160:40\)
\(=4\)
d
\(=798+100:\left[16-2\cdot\left(25-22\right)\right]\)
\(=798+100:\left(16-2\cdot3\right)\)
\(=798+100:\left(16-6\right)\)
\(=798+100:10\)
\(=798+10\)
\(=808\)
thực hiện phép tính : ( tính nhanh nếu có thể )
a) \(\left(\frac{11}{12}:\frac{33}{16}\right).\frac{3}{5}+\frac{7}{23}.\left[\left(\frac{-8}{6}+\frac{-45}{18}\right)\right]\)
b) \(\left(\frac{-2}{3}+\frac{3}{7}\right):\frac{4}{5}+\left(\frac{-1}{3}+\frac{4}{7}\right):\frac{4}{5}\)
c) \(\frac{5}{9}:\left(\frac{1}{11}-\frac{5}{22}\right)+\frac{5}{9}:\left(\frac{1}{15}-\frac{2}{3}\right)\)
d) \(\frac{-3}{4}.\frac{12}{-5}.\frac{-25}{6}+\left(-2\right).\frac{-38}{21}.\frac{-7}{4}.\frac{-3}{8}\)
Tính:
a) \(\left(\sqrt{1\dfrac{9}{16}}-\sqrt{\dfrac{9}{16}}\right):5\)
b) \(\left(\sqrt{3}-2\right)^2\left(\sqrt{3}+2\right)^2\)
c) \(\left(11-4\sqrt{3}\right)\left(11+4\sqrt{3}\right)\)
d) \(\left(\sqrt{2}-1\right)^2-\dfrac{3}{2}\sqrt{\left(-2\right)^2}+\dfrac{4\sqrt{2}}{5}+\sqrt{1\dfrac{11}{25}}.\sqrt{2}\)
e) \(\left(1+\sqrt{2021}\right)\sqrt{2022-2\sqrt{2021}}\)
a,\(\left(\sqrt{1\dfrac{9}{16}}-\sqrt{\dfrac{9}{16}}\right):5=\left(\sqrt{\dfrac{25}{16}}-\dfrac{3}{4}\right):5=\left(\dfrac{5}{4}-\dfrac{3}{4}\right):5\)
\(=\dfrac{1}{2}:5=\dfrac{1}{10}\)
b,\(\left(\sqrt{3}-2\right)^2\left(\sqrt{3}+2\right)^2=\left[\left(\sqrt{3}-2\right)\left(\sqrt{3}+2\right)\right]^2\)
\(=\left[3-4\right]^2=1\)
c,\(\left(11-4\sqrt{3}\right)\left(11+4\sqrt{3}\right)=11^2-\left(4\sqrt{3}\right)^2\)
\(=121-48=73\)
d,\(\left(\sqrt{2}-1\right)^2-\dfrac{3}{2}\sqrt{\left(-2\right)^2}+\dfrac{4\sqrt{2}}{5}+\sqrt{1\dfrac{11}{25}}.\sqrt{2}\)
\(=2-2\sqrt{2}+1-3+\dfrac{4\sqrt{2}}{5}+\sqrt{\dfrac{36}{25}.2}\)
\(=-2\sqrt{2}+\dfrac{4\sqrt{2}+6\sqrt{2}}{5}\)
\(=-2\sqrt{2}+\dfrac{10\sqrt{2}}{5}=-2\sqrt{2}+2\sqrt{2}=0\)
e,\(\left(1+\sqrt{2021}\right)\sqrt{2022-2\sqrt{2021}}\)
\(=\left(1+\sqrt{2021}\right)\sqrt{2021-2\sqrt{2021}.1+1}\)
\(=\left(1+\sqrt{2021}\right)\sqrt{\left(\sqrt{2021}-1\right)^2}\)
\(=\left(1+\sqrt{2021}\right)\left(\sqrt{2021}-1\right)\)
\(=\sqrt{2021}-1+\sqrt{2021^2}-\sqrt{2021}=2020\)
rút gon
a,\(\frac{2.5^{22}-9.5^{21}}{25^{10}}\)
b,\(\frac{5\left(3.7^{15}-19.7^{14}\right)}{7^{16}+3.7^{15}}\)
c,\(\frac{\left(\left(-2\right)^2\right)^3.\left(-4\right)^2}{\left(-2\right)^3.\left(-2\right)^2}\)
d,\(\frac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
e,\(2^3+3.\left(\frac{1}{8}\right)^0-\left(\frac{1}{2^2}\right).4+\left[\left(-2\right)^2:\frac{1}{2}\right].8\)
f,\(\frac{\left(\frac{2}{5}\right)^7.5^5+\left(\frac{9}{4}\right)^3:\left(\frac{3}{16}\right)^3}{2^7.5^2+512}\)
Cũng khuya rồi , mình làm câu 1 thôi nhé !
\(\frac{2.5^{22}-9.5^{21}}{25^{10}}=\frac{2.5^{22}-9.5^{21}}{\left(5^2\right)^{10}}\)
\(\frac{5^{21}.\left(2.5-9\right)}{5^{20}}=5.\left(10-9\right)=5\)
\(\text{Thực hiện các phép tính sau một cách hợp lý:}\)
\(a\)) \(\left(10^2+11^2+12^2\right):\left(13^2+14^2\right)\)
\(b\)) \(1.2.3...9-1.2.3...8-1.2.3...7.8^2\)
\(c\)) \(\dfrac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
\(d\)) \(1152-\left(374+1152\right)+\left(-65+374\right)\)
\(e\)) \(13-12+11+10-9+8-7-6+5-4+3+2-1\)
A=\(\left(1-\frac{1}{4}\right)\left(1-\frac{1}{9}\right)\left(1-\frac{1}{16}\right).....\left(1-\frac{1}{100}\right)\)
B=\(\left(1+\frac{1}{3}\right)\left(1+\frac{1}{8}\right)+\left(1+\frac{1}{15}\right)......\left(1+\frac{1}{100}\right)\)
D=\(\frac{8}{9}.\frac{15}{16}.\frac{24}{25}.....\frac{2499}{2500}\)
Tính :
a) \(5+\left(-7\right)+9+\left(-11\right)+13+\left(-15\right)\)
b) \(\left(-6\right)+8+\left(-10\right)+12+\left(-14\right)+16\)
a)
\(5+\left(-7\right)+9+\left(-11\right)+13+\left(-15\right)\)
\(=\left[5+\left(-7\right)\right]+\left[9+\left(-11\right)\right]+\left[13+\left(-15\right)\right]\)
\(=\left(-2\right)+\left(-2\right)+\left(-2\right)=-6\)
b)
\(\left(-6\right)+8+\left(-10\right)+12+\left(-14\right)+16\)
\(=\left[\left(-6\right)+8\right]+\left[\left(-10\right)+12\right]+\left[\left(-14\right)+16\right]\)
\(=2+2+2=6\)
a,\(\frac{-6}{21}.\frac{3}{2}\)
b,\(\left\{-3\right\}.\left\{\frac{-7}{12}\right\}\)
c,\(\left\{\frac{11}{12}:\frac{33}{16}\right\}.\frac{3}{5}\)
d,\(\sqrt{\left\{-7\right\}^2}+\sqrt{\frac{2}{16}}-\frac{3}{2}\)
e,\(\frac{1}{2}.\sqrt{100}-\sqrt{\frac{1}{16}}+\left\{\frac{1}{3}\right\}^0\)
a) \(\frac{-6}{21}.\frac{3}{2}=-\frac{3}{7}\) b) \(\left(-3\right).\left(\frac{-7}{12}\right)=\frac{21}{12}=\frac{7}{4}\)
c) \(\left(\frac{11}{12}:\frac{33}{16}\right).\frac{3}{5}=\frac{11}{12}.\frac{16}{33}.\frac{3}{5}=\frac{4}{15}\)
d) \(\sqrt{\left(-7\right)^2}+\sqrt{\frac{2}{16}}=7+\sqrt{\frac{1}{8}}\)
c) \(\frac{1}{2}.\sqrt{100}-\sqrt{\frac{1}{16}}+\left(\frac{1}{3}\right)^0=\frac{1}{2}.10-\frac{1}{4}+1=5\frac{3}{4}\)