Tim x:
(2x4 +2):2=X
tim x
x:2+x:4x6+x:2x4
x:2 +x:4x6 +x :2x4 = ?
=> x:2+x:24+x:8 = ?
=> x:(2+24+8) =?
=> x:34 = ?
(đề bài thiếu hả bạn)
tim X:
3/2x4/7-X=2/3
giúp mình với nhanh lên mình cần gấp lắm.
\(\frac{3}{2}\times\frac{4}{7}-x=\frac{2}{3}\)
\(\frac{6}{7}-x=\frac{2}{3}\)
\(x=\frac{6}{7}-\frac{2}{3}\)
\(x=\frac{18}{21}-\frac{14}{21}\)
\(x=\frac{4}{21}\)
\(\frac{3}{2}\chi\frac{4}{7}-x=\frac{2}{3}\)
\(\frac{6}{7}-x=\frac{2}{3}\)
\(x=\frac{6}{7}-\frac{2}{3}\)
\(x=\frac{4}{21}\)
tim tich: A= (1+1/1 x 3)x(1+1/2x4)x(1+1/3x5)x............x(1+1/2011x2013)
\(A=\left(1+\frac{1}{1.3}\right).\left(1+\frac{1}{2.4}\right).\left(1+\frac{1}{3.5}\right)...\left(1+\frac{1}{2011.2013}\right)\)
\(A=\frac{4}{1.3}.\frac{9}{2.4}.\frac{16}{3.5}...\frac{4048144}{2011.2013}\)
\(A=\frac{2.2}{1.3}.\frac{3.3}{2.4}.\frac{4.4}{3.5}...\frac{2012.2012}{2011.2013}\)
\(A=\frac{2.3.4...2012}{1.2.3...2011}.\frac{2.3.4...2012}{3.4.5...2013}\)
\(A=2012.\frac{2}{2013}=\frac{4024}{2013}\)
tim tich: A= (1+1/1 x 3)x(1+1/2x4)x(1+1/3x5)x............x(1+1/2011x2013)
Ta có :
\(A=\left(1+\dfrac{1}{1.3}\right)\left(1+\dfrac{1}{2.4}\right)\left(1+\dfrac{1}{3.5}\right).................\left(1+\dfrac{1}{2011.2013}\right)\)
\(A=\left(\dfrac{3}{3}+\dfrac{1}{3}\right)\left(\dfrac{8}{8}+\dfrac{1}{8}\right)................\left(\dfrac{9999}{9999}+\dfrac{1}{9999}\right)\)
\(A=\dfrac{4}{3}.\dfrac{9}{8}...............\dfrac{10000}{9999}\)
\(A=\dfrac{4.9.................10000}{3.8.............9999}\)
\(A=\dfrac{2.2.3.3................100.100}{1.3.2.4...............99.101}\)
\(A=\dfrac{2.100}{101}=\dfrac{200}{101}\)
~ Chúc bn học tốt ~
tim tich: A= (1+1/1 x 3)x(1+1/2x4)x(1+1/3x5)x............x(1+1/2011x2013)
P(x)=2x4-x-2x3+1
Q(x)=-2x4+x2+5
Tính P(x)+Q(x) bằng 2 cách
Giúp mik với ạ!
2 cách thì cách 1 là tính theo cột dọc ( đặt tính ak ) , cách 2 là tính như bth ( cậu tự làm nha )
đáp án : -2x^3 + x^2 -x + 6
2) (x + 40) x15 = 5 ^ 2 x 3^2x4
(x + 40) . 15 = 5² . 3² . 4
(x + 40) . 15 = 25 . 9 . 4
(x + 40) . 15 = 900
x + 40 = 900 : 15
x + 40 = 60
x = 60 - 40
x = 20
( x + 40 ) x 15 = 52 x 32 x 4
⇒ ( x + 40 ) x 15 = 25 x 9 x 4
⇒ ( x + 40 ) x 15 = 900
⇒ x + 40 = 60
⇒ x = 20.
Vậy x = 20.
X:2+X:4x6+X:2x4=8
Xx0,5+Xx0,25x6+Xx0,5x4=8
Xx0,5+Xx1,5+Xx2=8
Xx(0,5+1,5+2)=8
Xx4 =8
X =8:4
X =2
các cậu giải cho tớ với.mai học rồi nhé ai trả lời tớ tick cho
tim tich: A= (1+1/1 x 3)x(1+1/2x4)x(1+1/3x5)x............x(1+1/2011x2013)
A= (1+1/1 x 3)x(1+1/2x4)x(1+1/3x5)x............x(1+1/2011x2013)
\(=\left(\frac{3}{3}+\frac{1}{3}\right)\left(\frac{8}{8}+\frac{1}{8}\right)....\left(\frac{4048143}{4048143}+\frac{1}{4048143}\right)\)
\(=\frac{4}{3}\cdot\frac{9}{8}\cdot...\cdot\frac{4048144}{4048143}\)
\(=\frac{4\cdot9\cdot....\cdot4048144}{3\cdot8\cdot....\cdot4048143}\)
\(=\frac{2\cdot2\cdot3\cdot3\cdot....\cdot2012\cdot2012}{1\cdot3\cdot2\cdot4\cdot....\cdot2011\cdot2013}\)
\(=\frac{2\cdot2012}{2013}=\frac{4024}{2013}\)