Tìm Số Tự Nhiên X Thỏa (2x-15)^5=(2x-15)^3 - Hoc247

(2x-15)5 = ( 2x- 15)3

(2x-15)5- (2x-15)3=0

(2x-15)3 . 1-(2x-15)2=0

(2x-15)3.[ 1- (2x-15)2 ] = 0

\(\Rightarrow\) (2x-15)3=0 ( th1)

hoặc 1- (2x-15)2=0 (th2)

(th1) (2x-15)3= 0 (th2) 1-(2x-15)2=0

\(\Rightarrow\)(2x-15)3=03 -(2x-15)2=0-1

2x-15=0 -(2x-15)2=-1

2x =0+15 (2x-15)2=1

2x=15 \(\Rightarrow\) (2x-15)2=12

x=15:2 (2x-15)2=(-1)2

x=7,5 \(\Rightarrow\) 2x-15=1 \(\Rightarrow\) 2x= 1+ 15\(\Rightarrow\) 2x=16

\(\Rightarrow\) 2x-15= -1\(\Rightarrow\) 2x= -1+15\(\Rightarrow\) 2x=14

\(\Rightarrow\) x=16:2 \(\Rightarrow\) x=8

\(\Rightarrow\) x= 14:2\(\Rightarrow\) x=7

Vậy x = 7,5; x=8;x=7

Từ khóa » Tìm X Thuộc N Biết (2x-15)^5=(2x-15)^3