a. \(3x^n\left(6x^{n-3}+1\right)-2x^n\left(9x^{n-3}-1\right)\))
Rút gọn biểu thức
\(3x^n\left(6x^{n-3}+1\right)-2x^n\left(9x^{n-3}-1\right)\)
\(=\left(18x^{2n-3}+3x^n\right)-\left(18x^{2n-3}-2x^n\right)\)
\(=18x^{2n-3}+3x^n-18x^{2n-3}+2x^n\)
\(=\left(18x^{2n-3}-18x^{2n-3}\right)+\left(3x^n+2x^n\right)\)
\(=5x^n\)
\(=18x^{2n-3}+3x^n-18x^{2n-3}+2x^n=5x^n\)
\(3x^n\left(6x^{n-3}+1\right)-2x^n\left(9x^{n-3}-1\right)\)
\(3x^n\left(6x^{n-3}+1\right)-2x^n\left(9x^{n-3}-1\right)\)
\(=3x^n\cdot6x^{n-3}+3x^n-2x^n\cdot9x^{n-3}+2x^n\)
\(=18x^{2n-3}+3x^n-18^{2x-3}+2x^n\)
\(=3x^n+2x^n\)
\(=5x^n\)
thực hiện phép tính
\(3x^n\left(6x^{n-3}+1\right)-2x^n\left(9x^{n-3}-1\right)\))
\(3x^n\left(6x^{n-3}+1\right)-2x^n\left(9x^{n-3}-1\right)\)
\(=18x^{2n-3}+3x^n-18x^{2n-3}+2x^n\)
\(=3x^n+2x^n\)
\(=5x^n\)
\(3x^n\left\{6x^{n-3}+1\right\}-2x^n\left\{9x^{n-3}-1\right\}\)
em can giai luon nhe
thu gọn:
\(3x^n.\left(6x^{n-3}+1\right)-2x^n.\left(9x^{n-3}-1\right)\)
\(3x^n.\left(6x^{n-3}+1\right)-2x^n.\left(9x^{n-3}-1\right)\)
\(=18x^{n+n-3}+3x^n-18x^{n+n-3}+2x^n\)
\(=18x^{2n-3}+3x^n-18^{2n-3}+2x^n\)
\(=3x^n+2x^n=x^n\left(3+2\right)=5x^n\)
Rút gọn biểu thức:
\(3x^n\left(6x^{n-3}+1\right)-2x^n\left(9x^{n-3}-1\right)\)
\(5^{n+1}-4.5^n\)
Ta có: \(5^{n+1}-4.5^n=5^n.5-4.5^n=\left(5-4\right)5^n=5^n\)
CHÚC BẠN HỌC TỐT.........
a) 3x\(^n\) (6x\(^{n-3}\)+1) - 2x\(^n\) ( 9x\(^{n-3}\) - 1)
= 18x\(^{n-2}\) + 3x\(^n\) - 18x\(^{n-2}\) + 2x\(^n\)
= 5x\(^n\)
b) 5\(^{n+1}\) - 4.5\(^n\)
= 5\(^n\) . ( 5-4) = 5\(^n\)
1. Thực hiện phép tính:
a. \(3x^n\left(6x^{n-3}+1\right)-2x^n\left(9x^{n-3}-1\right)\)
b. \(5^{n+1}-4.5^n\)
c. \(6^2.6^4-4^3\left(3^6-1\right)\)
a:
=\(18x^{2n-3}+3x^n-18^{2n-3}+2x^n\)
\(=5x^n\)
b: \(=5^n\cdot5-4\cdot5^n=5^n\)
c: \(=6^6-4^3\cdot3^6+4^3\)
\(=2^6\cdot3^6-2^6\cdot3^6+64=64\)
Rút gọn các biểu thức sau :
a) \(6x^n\left(x^2-1\right)+2x^3\left(3x^{n+1}+1\right)\)
b) \(3x^{n-2}\left(x^{n+2}-y^{n+2}\right)+y^{n+2}\left(3x^{n-2}-y^{n-2}\right)\)
c) \(x^{n-3}\left(x-y\right)+y\left(x^{n-3}+x^{n-3}y^{n-1}\right)\)
giải pt :
a,\(\left(6x-5\right)\sqrt{x+1}-\left(6x+2\right)\sqrt{x-1}+4\sqrt{x^2-1}=4x-3\)
b, \(\left(9x-2\right)\sqrt{3x-1}+\left(10-9x\right)\sqrt{3-3x}-4\sqrt{-9x^2+12x-3}=4\)
c, \(\left(13-4x\right)\sqrt{2x-3}+\left(4x-3\right)\sqrt{5-2x}=2+8\sqrt{-4x^2+16x-15}\)