tính:
\(\dfrac{1.98+2.97+3.96+....+96.3+97.2+98.1}{1.2+2.3+3.4+4.5+.....+98.99}\)
Những câu hỏi liên quan
Chứng minh rằng :\(\dfrac{1.98+2.97+3.96+...+96.3+97.2+98.1}{1.2+2.3+3.4+...+96.97+97.98+98.99}=\dfrac{1}{2}\)
Đặt A=1.98+2.97+3.96+...+96.3+97.2+98.1
B=1.2+2,3+3.4+...+96.97+97.98+98.99
Ta có: A=1+(1+2)+...+(1+2+3+...+97+98)
=\(\dfrac{1.2}{2}+\dfrac{2.3}{2}+...+\dfrac{98.99}{3}\)
=\(\dfrac{1.2+2.3+3.4+4.5+...+98.99}{2}\)=\(\dfrac{B}{2}\)
=>E=\(\dfrac{B}{2}\):2=\(\dfrac{1}{2}\)
Đúng 4
Bình luận (0)
tính
\(\frac{1.98+2.97+3.96+...+96.3+97.2+98.1}{1.2+2.3+3.4+...+98.99}\)
Chứng minh rằng: B = \(\frac{1.98+2.97+3.96+...+96.3+97.2+98.1}{1.2+2.3+3.4+...+96.97+97.98+98.99}=\frac{1}{2}\)
Chứng minh rằng \(\frac{1.98+2.97+3.96+...+96.3+97.2+98.1}{1.2+2.3+3.4+...+96.97+97.98+98.99}=\frac{1}{2}\)
CMR:
\(B=\dfrac{1.98+2.97+3.96+...+96.3+97.2+98.1}{1.2+2.3+3.4+...+96.97+97.98+98+99}=\dfrac{1}{2}\)
Chứng minh rằng \(\frac{1.98+2.97+3.96+...+96.3+97.2+98.1}{1.2+2.3+3.4+...+96.97+97.98+98.99}\)=1/2
Tính \(A=\frac{1.98+2.97+3.96+...+97.2+98.1}{1.2+2.3+3.4+...+97.98+98.99}\)
CMR:
\(B=\dfrac{1.98+2.97+3.96+...+96.3+97.2+98.1}{1.2+2.3+3.4+...+96.97+97.98+98+99}=\dfrac{1}{2}\)
B=1.98+2.97+3.96+......+98.1/1.2+2.3+3.4+....+98.99 = ?
\(\text{Đặt C = 1.2 + 2.3 + 3.4 + ..... +98.99 }\)
\(\text{ Và A = 1.98 + 2.97 + 3.96 + .... + 98.1 }\)
\(\text{Khi đó : }A=1+\left(1+2\right)+....+\left(1+2+...+98\right)\)
\(=\frac{1.2}{2}+\frac{2.3}{2}+\frac{3.4}{2}+....+\frac{98.99}{2}\)
\(=\frac{1.2+2.3+3.4+....+98.99}{2}=\frac{C}{2}\)
\(\Rightarrow B=\frac{C}{\frac{2}{C}}=\frac{1}{2}\)
Đúng 0
Bình luận (0)
Ta có;
1+(1+2)+(1+2+3)+.....+(1+2+3+4+5+...+98)
Đúng 0
Bình luận (0)
Xem thêm câu trả lời