\(S=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2011}-\frac{1}{2012}+\frac{1}{2013}\)

\(S=1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2012}+\frac{1}{2013}-2\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2012}\right)\)

\(S=1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2012}+\frac{1}{2013}-\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{1006}\right)\)

\(S=\frac{1}{1007}+\frac{1}{1008}+...+\frac{1}{2013}\)

\(\Rightarrow\left(S-P\right)^{2013}=0^{2013}=0\).

à há mình ko biết

Khó quá ????????????????????????????????????????????????????????????????????????????

S=\(\left(1+\frac{1}{3}+...+\frac{1}{2013}\right)-\left(\frac{1}{2}-\frac{1}{4}-...-\frac{1}{2012}\right)\)

S=\(\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2013}\right)-2\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2012}\right)\)

S=\(\left(\text{​​}\text{​​}\text{​​}1+\frac{1}{2}+...+\frac{1}{2013}\right)-1-\frac{1}{2}-...-\frac{1}{2012}\)

S=\(\frac{1}{1007}+\frac{1}{1008}+...+\frac{1}{2013}\)

=>S=P

=>S-P=0

=>(S-P)^2013=0

toi lam roi 144                  100% dung 

f(100)=> x=100

=>x+1=101

thay x+1=101 ta được:

f(100)=x⁸-(x+1)x⁷+(x+1)x⁶-(x+1)x⁵+...+(x+1)x²-(x+1)x+25

=x⁸-(x⁸+x⁷)+(x⁷+x⁶)-(x⁶+x⁵)+...+(x³+x²)-(x²+x)+25

=x⁸-x⁸-x⁷+x⁷+x⁶-x⁶-x⁵+...+x³+x²-x²-x+25

=-x+25

=-100+25

=-75

-75 nha

Cho góc XOY có số đo 70o. Tia OZ là tia phân giác của góc XOY. Gọi OT là tia đối của tia OX. Tính so đo góc TOH

H ở đâu thế

Mình làm thử, không biết có sai không, nếu sai thì cho mình đáp án rút kinh nghiệm nhé:

     \(\left(13\frac{9}{11}:\frac{38}{49}-5\frac{2}{11}:\frac{38}{49}\right):\left(\frac{49}{38}.\frac{5}{11}\right)\)   

\(=\left(\frac{152}{11}:\frac{38}{49}-\frac{57}{11}:\frac{38}{49}\right):\left(\frac{49}{38}.\frac{5}{11}\right)\)

\(=\left(\frac{196}{11}-\frac{147}{22}\right):\frac{245}{418}\)

\(=\frac{245}{22}:\frac{245}{418}=19\)