Tính A= $\frac{1}{2}$ .(1+$\frac{1}{1.3}$ ).(1+$\frac{1}{2.4}$ ).(1+$\frac{1}{3.5}$ ).......(1+$\frac{1}{2015.2017}$ )
1 câu trả lời
Đáp án:
CBHT^^
Giải thích các bước giải:
A =1/2. (1 +1/1.3 ) (1 +1/2.4 ) (1 +1/3.5 ) . . . (1 + 1/2015.2017)
A =1/2.4/5.9/8.16/15....4064256/4064255
A = 1/2. 2.2.3.3.4.4....2016.2016/3.8.15....4064255
A = 1/2. 2.2.3.3.4.4....2016.2016/1.3.2.4.3.5.....2015.2017
A = 1/2. 2.3.4....2016/1.2.3.....2015 . 2.3.4.....2016/3.4.5.....2017
A = 1/2 . 2016 . 2/12017
A = 2016/2017
