rút gọn B=\(\frac{x^{28}+x^{24}+x^{20}+...+x^4+1}{x^{30}+x^{28}+x^{26}+...+x^2+1}\)
Rút gọn biểu thức:
B=\(\frac{x^{28}+x^{24}+x^{20}+....+x^4+1}{x^{30}+x^{28}+x^{26}+....+x^2+1}\)
\(B=\frac{x^{28}+x^{24}+x^{20}+...+x^4+1}{x^{30}+x^{28}+x^{26}+...+x^2+1}\)
\(=\frac{x^{28}+x^{24}+x^{20}+...+x^4+1}{\left(x^{30}+x^{26}+x^{22}+...+x^6+x^2\right)+\left(x^{28}+x^{24}+x^{20}+...+x^4+1\right)}\)
\(=\frac{x^{28}+x^{24}+x^{20}+...+x^4+1}{x^2\left(x^{28}+x^{24}+x^{20}+...+x^4+1\right)+\left(x^{28}+x^{24}+x^{20}+...+x^4+1\right)}\)
\(=\frac{x^{28}+x^{24}+x^{20}+...+x^4+1}{\left(x^2+1\right)\left(x^{28}+x^{24}+x^{20}+...+x^4+1\right)}=\frac{1}{x^2+1}\)
tự làm mẹ đê hỏi lắm
\(\frac{^{^{x^{30}+x^{28}+x^{26}+.......+x^6+x^4+x^2+1}}}{x^{28}+x^{24}+x^{20}+......+x^8+x^4+1}\)
\(^{x^{ }28+x^{ }24+x^{ }20+...+x^{ }0\frac{ }{ }x^{ }30+x^{ }28+...+x^{ }0.}\)
rút gọn
các bn giúp mình nhanh nhé. Mình cần gấp
x^30+x^28+x^26+.........+x^4+x^2+1/x^28+x^24+x^20+.........+x^8+x^4+1
\(\frac{x^{30}+x^{28}+x^{26}+x^{24}+...+x^4+x^2+1}{x^{28}+x^{24}+x^{20}+...+x^8+x^4+1}=\frac{\left(x^{30}+x^{26}+x^{22}+...+x^2\right)+\left(x^{28}+x^{24}+...+x^4+1\right)}{x^{28}+x^{24}+x^{20}+...+x^4+1}\)
\(=\frac{x^2\left(x^{28}+x^{24}+...+x^4+1\right)+\left(x^{28}+x^{24}+...+x^4+1\right)}{x^{28}+x^{24}+...+x^4+1}\)
\(=\frac{\left(x^2+1\right)\left(x^{28}+x^{24}+...+x^4+1\right)}{x^{28}+x^{24}+...+x^4+1}\)
\(=x^2+1\)
1.tìm x để A nhập giá trị A=x/12
2-x^30+x^28+x^26+.....+x^4+x^2+1/b^28+x^24+x^20+....+x^1+x^4+1
Rút gọn biểu thức: B=x^28+x^24+.....+x^4+1
x^30+x^28+......+x^2+1
RÚT GỌN\(\frac{x^{24}+x^{20}+.......+x^4+1}{x^{26}+x^{24}+......+x^2+1}\)
\(\frac{x^{24}+x^{20}+...+x^4+1}{x^{26}+x^{24}+...+x^2+1}=\frac{x^{24}+x^{20}+...+x^4+1}{\left(x^{24}+x^{20}+...+x^4+1\right)+\left(x^{26}+x^{22}+...+x^2\right)}\)
\(=1-\frac{x^2\left(x^{24}+x^{20}+...+x^4+x^1\right)}{\left(1+x^2\right)\left(x^{24}+2^{20}+...+x^4+1\right)}=1-\frac{x^2}{1+x^2}\)
\(=\frac{1+x^2-x^2}{1+x^2}=\frac{1}{1+x^2}\)
Hoặc cách khác:
\(\frac{x^{24}+x^{20}+...+x^4+1}{x^{26}+x^{24}+...+x^2+1}=\frac{x^{24}+x^{20}+...+x^4+1}{\left(x^{24}+x^{20}+...+x^4+1\right)+x^2\left(x^4+x^{20}+...+x^4+1\right)}\)
\(=\frac{x^{24}+x^{20}+...+x^4+1}{\left(x^2+1\right)\left(x^{24}+x^{20}+...+x^4+1\right)}=\frac{1}{x^2+1}\)
Ở cách thứ 2,mình viết nhầm tí: \(x^2\left(x^4+x^{20}+...+x^4+1\right)\rightarrow x^2\left(x^{24}+x^{20}+...+x^4+1\right)\) giúp mình nha,Đánh thiếu số 2 : một lỗi sai chết người=)
Rút gọn phân thức
\(\frac{x^{24}+x^{20}+x^{16} +...+x^4+1}{x^{26}+x^{24}+x^{22}+...+x^2+1}\)
Rút gọn biểu thức:\(\frac{x^{24}+x^{20}+x^{16}+...+x^4+1}{x^{26}+x^{24}+x^{22}+...+x^2+1}\).
Ta nhận thấy mẫu của biểu thức trên là:
x26+x24+x22+...+x2+1=(x26+x22+...+x2)+(x24+x20+...+x4+1)
=x2(x24+x20+...+x16+...+1)+(x24+x20+...+x4+1)
=(x24+x20+...+1)(x2+1)
Như vậy\(\frac{x^{24}+x^{20}+x^{16}+...+1}{\left(x^{24}+x^{20}+...+1\right)\left(x^2+1\right)}\)=\(\frac{1}{x^2+1}\)
học giỏi vclllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll.......