cho a = 2^3 + 2^4 + 2^5 +...+2^18 ; b= 2^19 tìm x . biết a = b - x ( trình bày cách giải dùm mình nha )
tính
A=5*(2^2*3^2)^9*(2^2)^6-2*(2^2*3)^14*3^4/5*2^28*3^18-7*2^29*3^18
a,thuc hien phep tinh: 5*(2^2*3^2)^9*(2^2)^6-2*(2^2*3)^14*3^4/5*2^28*3^18-7*2^29*3^18
b,tim cac so nguyen n sao cho: n^2+5*n+9 la boi cua n+3
c,tim x,y nguyen sao cho: xy+2*x+y+11=0
2)tìm x:
a)x-2/3=4/5.3/4
b)x-11/18=0,2+7/18
c)-3/8x+3/10=4/5
d)3/5+2/5x=1
a) 16 . 36 - 16 . 37
b) 36 : 4 . 3 + 9 . 50
c) 2 . (5 . 16 - 18) + 36 : 18 . 2
d) 48 : 8 . 5 + 5 . 44
e) 5 . 4 - 18 : 3
f) 2 . 25 + 169 : 13 - 54 : 27
a) \(...=16.\left(36-37\right)=16.\left(-1\right)=-16\)
b) \(...=9.3+9.50=9.\left(3+50\right)=9.53=477\)
c) \(...=2.\left(\left(5.16-18\right)+36:18\right)=2.\left(70+2\right)=2.72=144\)
d) \(...=5\left(48:8+44\right)=5\left(6+44\right)=5.50=250\)
e) \(...=20-6=14\)
f) \(...=50+13-2=61\)
Cô tick xanh cho bạn Đức Trí, các câu khác em làm theo bạn vì bạn làm đúng còn câu c em làm theo cô nhé.
Câu c,
2.(5.16 - 18) + 36:18.2
= 2.(80 - 18) + 2.2
= 2.62 + 4
= 128
d) 48 : 8 . 5 + 5 . 44
= 6 . 5 + 5 . 44
= 5 . (6 + 44)
= 5 . 50
= 250
e) 5 . 4 - 18 : 3
= 20 - 6
= 14
f) 2 . 25 + 169 : 13 - 54 : 27
= 50 + 13 - 2
= 61
a, 1\(\dfrac{5}{18}\)+\(\dfrac{7}{25}\)-\(\dfrac{5}{18}\)+\(\dfrac{18}{25}\)-0, 75
b, \(\dfrac{2}{5}\).\(\dfrac{1}{3}\)-\(\dfrac{4}{3}\).\(\dfrac{2}{5}\)
c, (\(\dfrac{-1}{4}\)).( 6\(\dfrac{2}{11}\)) + 3 \(\dfrac{9}{11}\).(\(\dfrac{-1}{4}\))
d, 4. (-\(\dfrac{1}{2}\))\(^{3_{ }}\)-\(_{ }\)2. (\(\dfrac{-1}{2}\))\(^2\) + 3. (\(\dfrac{-1}{2}\)) + 1
e, \(\dfrac{1}{6}\)-(\(\dfrac{2}{3}\))\(^2\) + \(\dfrac{5}{18}\)
f, (\(\dfrac{4}{3}\)-\(\dfrac{3}{2}\))\(^2\)- 2.|-\(\dfrac{1}{9}\)| + (-\(\dfrac{5}{18}\))
e: \(=\dfrac{1}{6}-\dfrac{4}{9}+\dfrac{5}{18}=\dfrac{3-8+5}{18}=0\)
Đúng ghi Đ sai ghi S:
a,5 x 7/18 + 2/9 = 5 x 11/18=55/18
b,3/4 x (2/9+5/6) = 3/4 x 2/9 +3/4 x 5/6=1/6 + 5/8=19/24
a, 4 2/5 + 5 2/3 + 2 3/4 + 3/5 + 4/12 + 1/4 = ?
b, 41/27 x 13/18 - 13/18 x 14/27 =?
CAC BAN HAY LAM DIEN GIAI RA CHO MINH NHE ....... MINH RAT CAM ON CAC BAN
a)\(4\frac{2}{5}+5\frac{2}{3}+2\frac{3}{4}+\frac{3}{5}+\frac{4}{12}+\frac{1}{4}\)
\(=\left(4\frac{2}{5}+\frac{3}{5}\right)+\left(5\frac{2}{3}+\frac{4}{12}\right)+\left(2\frac{3}{4}+\frac{1}{4}\right)\)
\(=5+6+3=14\)
b)\(\frac{41}{27}\cdot\frac{13}{18}-\frac{13}{18}\cdot\frac{14}{27}\)
\(=\frac{13}{18}\cdot\left(\frac{41}{27}-\frac{14}{27}\right)\)
\(=\frac{13}{18}\cdot1=\frac{13}{18}\)
Thực hiện dãy tính:
a) ( 1/2 - 1/7 ) + -1/3 . 3 4/7 - 0.75
b) ( 6/14 - -18/36 - 5/15 ) : ( 0,2 - 1 4/ 5 )
c) 11/ 32 : ( 14/18 + 16/27) - (2/3 - 5/15 )
d) 4. ( -1/2 ) 2 - 2. ( - 2/3 ) 2 + 2 7/9 - (-18/48)
e) 1,4 . 15/49 - (4/5 + 2/3 ) : ( -2 1/5 )
g) -1/7. (9 1/2 - 8.75 ) : 2/7 + 0,675 : ( -1 2/3 )
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)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\)
=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\)
=\(0+\dfrac{5}{13}\)
=\(\dfrac{5}{13}\)
Cho A=5+5^2+5@3+5^4+....+5^18.Chứng minh rằng