\(2^4.5-\left[131-\left(130-4\right)^2\right]\)
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Tính giá trị của biểu thức sau:
a.\(2^4.5-\left[131-\left(13-4^2\right)\right]\)
b.\(\frac{-3}{5}+\frac{28.43}{5.56}+\frac{28.5}{5.24}-\frac{28.21}{5.63}\)
a)=16.5-[131-(13-16)]
=80-[131--3]
=80-134=-54
b
.ta có
=-3/5+28/5.43/56+28/5.5/24-28/5.21/63
=-3/5+28/5.(43/56+5/24-21/63)
=5.9/14=45/14
suy ra
biểu thức b có giá trị là 45/14
rút gọn các phân số sau
\(\dfrac{2.\left(-13\right).9.10}{\left(-3\right).4.\left(-5\right).26}\)
\(\dfrac{2^2.2^3.5^7}{2^3.3^4.5^6}\)
a: \(=\dfrac{-4\cdot13\cdot9\cdot5}{3\cdot4\cdot5\cdot2\cdot13}=\dfrac{3}{2}\)
b: \(=\dfrac{1}{2}\cdot\dfrac{1}{3}\cdot5=\dfrac{5}{6}\)
Tính
\(17^0+\left[5^{13}:5^{11}+\left(135-130\right)^3\right]\)
\(\left[36\cdot4-4\left(82-7\cdot11\right)^2:4\right]-2016\)
a,17^0 + [5^13 : 5^11 + (135 - 130)^3
= 1 + [ 5^2 + 5^3 ]
= 1 + 150
= 151
b, 36 . 4 − 4 (82−7.11)^2 : 4−2016^0
= 144 − 4.(82−77)^2 : 4 − 1
= 144 − 4 . 25 : 4 − 1
= 118
--T-T--
a) \(3^4.5^4-\left(15^2+1\right)\left(15^2-1\right)\)
b) \(x^4-12x^3+12x^2-12x+111\) tại x=11
c) \(\left(6x+1\right)^2+\left(6x-1\right)^2-2\left(1+6x\right)\left(6x-1\right)\)
d) \(3\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\)
Bài 2 : Tính :
a) 24 . 5 - \(\left[131.\left(13-4\right)^2\right]\)
b) 100 : \(\left\{230:\left[450-\left(4-5^3-5^2.25\right)\right]\right\}\)
c) 30 . \(\left\{175:\left[355-\left(135+37.5\right)\right]\right\}\)
a) 24.5 - [ 131. ( 13 - 4 )2 ]
=120 - [ 131 . 92 ]
=120 - [ 131 . 81 ]
=120 - 10611
= - 10491
b) 100 : {230:[450−(4−53−52.25)]}
= 100 : \(\left\{230:\left[450-\left(4-125-25.25\right)\right]\right\}\)
= \(100:\left\{230:\left[450-\left(4-125-625\right)\right]\right\}\)
= \(100:\left\{230:\left[450-\left(-746\right)\right]\right\}\)
=\(100:\left\{230:1196\right\}\)
= 100 : \(\dfrac{5}{26}\)= 520
c) 30 . {175:[355−(135+37.5)]}
= 30. \(\left\{175:\left[355-\left(135+185\right)\right]\right\}\)
= 30 . \(\left\{175:\left[355-320\right]\right\}\)
= 30 . \(\left\{175:35\right\}\)
= 30 .5 = 150
Tính nhanh :
\(B=\left(-\frac{1}{2}\right)-\left(-\frac{3}{5}\right)+\left(-\frac{1}{9}\right)+\frac{1}{131}-\left(-\frac{2}{7}\right)+\frac{4}{35}-\frac{7}{18}\)
\(\left(-\frac{1}{2}\right)-\left(-\frac{3}{5}\right)+\left(-\frac{1}{9}\right)+\frac{1}{131}-\left(-\frac{2}{7}\right)+\frac{4}{35}-\frac{7}{18}\)
tính nhanh
\(\frac{-1}{2}-\frac{-3}{5}-\frac{1}{9}+\frac{1}{131}+\frac{2}{7}+\frac{4}{35}-\frac{7}{18}=\left(-\frac{1}{2}-\frac{1}{9}-\frac{7}{18}\right)+\left(\frac{3}{5}+\frac{2}{7}+\frac{4}{35}\right)+\frac{1}{131}\)\(=\left(\frac{-9}{18}-\frac{2}{18}-\frac{7}{18}\right)+\left(\frac{21}{35}+\frac{10}{35}+\frac{4}{35}\right)+\frac{1}{131}=\frac{-18}{18}+\frac{35}{35}+\frac{1}{131}=-1+1+\frac{1}{131}=\frac{1}{131}\)
Thực hiện phép tính( tính nhanh nếu có thể):
a/ 26 + 173 + 74 + 27
b/ 75.37 + 89.46 + 75.52 - 89.21
c/ \(2^7:2^2+5^4:5^3.2^4-3.2^5\)
d/ \(100:\left\{250:\left[450-\left(4.5^3-2^2.25\right)\right]\right\}\)
a) \(26+173+74+27\)
\(=\left(26+74\right)+\left(173+27\right)\)
\(=100+200\)
\(=300\)
b) \(75\cdot37+89\cdot46+75\cdot52-89\cdot21\)
\(=75\cdot\left(37+52\right)+89\cdot\left(46-21\right)\)
\(=75\cdot89+89\cdot25\)
\(=89\cdot\left(75+25\right)\)
\(=89\cdot100\)
\(=8900\)
c) \(2^7:2^2+5^4:5^3\cdot2^4-3\cdot2^5\)
\(=2^{7-2}+5^{4-3}\cdot2^4-3\cdot2^5\)
\(=2^5+5\cdot2^4-3\cdot2^5\)
\(=2^4\cdot\left(2+5-3\cdot2\right)\)
\(=2^4\cdot\left(7-6\right)\)
\(=2^4\)
\(=16\)
d) \(100:\left\{250:\left[450-\left(4\cdot5^3-2^2\cdot25\right)\right]\right\}\)
\(=100:\left\{250:\left[450-\left(4\cdot5^3-4\cdot5^2\right)\right]\right\}\)
\(=100:\left[250:\left(450-4\cdot5^2\cdot4\right)\right]\)
\(=100:\left[250:\left(450-400\right)\right]\)
\(=100:\left(250:50\right)\)
\(=100:5\)
\(=20\)
\(\left(\frac{2}{2.3}-1\right)\left(\frac{2}{3.4}-1\right)\left(\frac{2}{4.5}\right)........\left(\frac{2}{n\left(n+1\right)}-1\right)\left(n\in N\ne0,n\ge2\right)\)