đề: tính
a, { [ 6,2 : 0,31 - \(\frac{5}{6}.0.9\)).0,2 + 0.15 ] : 0,2 } : [ ( 2+\(1\frac{4}{11}\) . 0,22b: 0,1 ) . \(\frac{1}{33}\)
b, 0,4(3) + 0,6(2) . \(2\frac{1}{2}\) . [ ( \(\frac{1}{2}+\frac{1}{3}\)) : 0,5(8) ] : \(\frac{50}{53}\)
Tính:
a)\(\left\{\left[\left(6,2:0,31-\frac{5}{6}.0,9\right).0,2+0,15\right]:0,2\right\}:\left[\left(2+1\frac{4}{11}:0,1\right).\frac{1}{33}\right]\)
b)\(0,4\left(3\right)+0,6\left(2\right)-2\frac{1}{2}.\left[\left(\frac{1}{2}+\frac{1}{3}:0,5\left(8\right)\right)\right]:\frac{50}{53}\)
c)\(\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{0,625-0,5+\frac{5}{11}+\frac{5}{12}}\)
c) \(\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{0,625-0,5+\frac{5}{11}+\frac{5}{12}}=\frac{3\left(0,125-0,1+\frac{1}{11}+\frac{1}{12}\right)}{5\left(0,123-0,1+\frac{1}{11}+\frac{1}{12}\right)}=\frac{3}{5}\)
tính
a, A = \(\frac{3^6.4.5^4-15^{13}.5^{-3}}{27^4.25^3+45^6}\)
b , B = \(\frac{\left[\left(6,2:0,31-\frac{5}{6}.0,9\right).0,2+0,15\right]:0,2}{\left(2+1\frac{4}{11}.0,22:0,1\right).\frac{1}{33}}\)
Tính:
{[(6,2 : 0,31 - \(\frac{5}{6}\). 0,9). 0,2 + 0,15]: 0,2} : [(2 + \(1\frac{4}{11}\). 0,22 : 0,1) . \(\frac{1}{33}\)]
{[(6,2:0,31-5/6.0,9).0,2+0,15]:0,2}:[(2+1/4/11.0,22:0,1).1/33]
={[(6,2:0,31-0,75).0,2+0,15]:0,2}:[(2+0,3:0,1).1/33]
={[19,25.0,2+0,15]:0,2}:[5.1/33]
={4:0,2}:5/33
=20:5/33
=132
bài 1 : Tính bằng cách hợp lí
a) \(\frac{0,4+\frac{2}{7}-\frac{2}{11}}{0,6+\frac{3}{7}-\frac{3}{11}}+\frac{0,25-0,2+\frac{1}{7}}{0,75-0,6+\frac{3}{7}}\)
Bài 1:
a) (-0,25) . 0,45 . 0,4 . (-0,125) . 0,55 . (-8)
b) [ 20,83 . 0,2 + (-9,17 . 0,2) ] : [ 2,47 . 0,5 - (-3,53 . 0,5) ]
c) \(\frac{(9\frac{3}{4}\div5,2+3,4\times2\frac{7}{34})\div(-1\frac{9}{16})}{\left(-0,31\right).8\frac{2}{5}-5,61\div\left(-27\frac{1}{2}\right)}\)
Tính:
\(\left\{\left[\left(6,2:0,31-\dfrac{5}{6}.0,9\right).0,2+0,15\right]:0,2\right\}:\left[\left(2+1\dfrac{4}{11}.0,22:0,1\right).\dfrac{1}{33}\right]\)
b) \(0,4\left(3\right)+0,6\left(2\right).2\dfrac{1}{2}.\left[\left(\dfrac{1}{2}+\dfrac{1}{3}\right):0,5\left(8\right)\right]:\dfrac{50}{53}\)
a: \(=\left\{\left[\left(20-\dfrac{1}{4}\right)\cdot0.2\right]+\dfrac{3}{20}\right\}\cdot5:\left[\left(2+\dfrac{25}{11}\cdot\dfrac{22}{100}\cdot10\right)\cdot\dfrac{1}{33}\right]\)
\(=\left\{\left[\dfrac{79}{20}+\dfrac{3}{20}\right]\right\}\cdot5:\left[\dfrac{356}{55}\cdot\dfrac{1}{33}\right]\)
\(=\dfrac{82}{20}\cdot5:\dfrac{3856}{1815}\simeq104,516\)
b: \(=\dfrac{13}{30}+\dfrac{28}{45}\cdot\dfrac{5}{2}\cdot\left[\dfrac{5}{6}:\dfrac{53}{90}\right]\cdot\dfrac{53}{50}\)
\(=\dfrac{13}{30}+\dfrac{14}{9}\cdot\dfrac{3}{2}=\dfrac{83}{30}\)
a) {[(6,2:0,31- .0,9).0,2 + 0,15]:0,2}: [( 2 + 1 . 0,22 : 0,1) . ]
b) 0,4(3) + 0,6(2). 2 . [( + ) : 0,5(8)] :
a: \(=\left\{\left[\left(6.2:0.31-0.9\right)\cdot0.2+0.15\right]\cdot5\right\}:\left(2+1\cdot2,2\right)\)
\(=\left\{\left[\left(20-0.9\right)\cdot0.2+0.15\right]\cdot5\right\}:4.2\)
\(=3.97\cdot5:4.2=\dfrac{397}{84}\)
b: Bạn ghi lại đề đi bạn
{[(6,2 /0,31 -5/6*0,9)*0,2 +0,15 ]/0,2}/[(2+15/11*0,22/0,1)*1/33]
Bài tập nâng cao
Bài 1: Tính
a)\(\left\{\left[\left(6,2:0,31-\frac{5}{6}.0,9\right).0,2+0,15\right]:0,2\right\}\left[\left(2+1\frac{4}{11}.0,22:0,1\right).\frac{1}{33}\right]\)
b)\(0,4\left(3\right)+0,6\left(2\right).2\frac{1}{2}.\left[\left(\frac{1}{2}+\frac{1}{3}\right):0.5\left(8\right)\right]:\frac{50}{53}\)
c)\(\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{0,625-0,5+\frac{5}{11}+\frac{5}{12}}\)
Bài 2: Tìm 2 số a,b biết
a)\(\frac{a}{5}=\frac{b}{4};a^2-b^2=1\)
b)\(\frac{a}{2}=\frac{b}{3}=\frac{c}{4};a^2-b^2+2c^2=108\)
Bài 3: Cho a/b=c/d chứng minh rằng
a)\(\frac{ab}{cd}=\frac{a^2+b^2}{c^2+d^2}\) b)\(\frac{ac}{bd}=\frac{a^2+c^2}{b^2+d^2}\) c)\(\frac{7a^2+3ab}{11a^2-8b^2}=\frac{7c^2+3cd}{11c^2-8d^2}\)
Bài 4: Tìm giá trị nhỏ nhất
a) A=3./1-2x/-5 b)\(B=\left(2x^2+1\right)^4-3\) c) C= /x-1/2/+(y+2)^2+11
Bài 5: Tìm giá trị lớn nhất trong các biểu thức sau
a) C=-/2-3x/+1/2 b) D= -3-/2x+4/
Bài 6: Cho bốn số a,b,c,d thảo mãn điểu kiện b^2=ac; c^2=bd. Chứng minh
a^3+b^3+c^3=a/d
b^3+c^3+d^3
Dài dễ sợ ghê, có làm thì đến tối mới xong.sory