tính nhanh :
a,( 1 – 1/2 ) x (1 – 1/3 ) x ( 1- 1/4 ) x (1 -1/5 ) x ( 1 – 1/6 ) x ( 1 – 1/7 )
tính nhanh : a,( 1 – 1/2 ) x (1 – 1/3 ) x ( 1- 1/4 ) x (1 -1/5 ) x ( 1 – 1/6 ) x ( 1 – 1/7 )
By Alexandra
By Alexandra
tính nhanh :
a,( 1 – 1/2 ) x (1 – 1/3 ) x ( 1- 1/4 ) x (1 -1/5 ) x ( 1 – 1/6 ) x ( 1 – 1/7 )
(1 – 1212) x (1 – 1313) x (1 – 1414) x (1 – 1515) x ( 1 – 1616) x (1 – 1717)
= 1212 x 2323 x 3434 x 4545 x 5656 x 6767
= 1.2.3.4.5.62.3.4.5.6.71.2.3.4.5.62.3.4.5.6.7
= 1717
CHÚC BẠN HỌC TỐT
Đáp án:
Giải thích các bước giải
(1 – $\frac{1}{2}$) x (1 – $\frac{1}{3}$) x (1 – $\frac{1}{4}$) x (1 – $\frac{1}{5}$) x ( 1 – $\frac{1}{6}$) x (1 – $\frac{1}{7}$)
= $\frac{1}{2}$ x $\frac{2}{3}$ x $\frac{3}{4}$ x $\frac{4}{5}$ x $\frac{5}{6}$ x $\frac{6}{7}$
= $\frac{1.2.3.4.5.6}{2.3.4.5.6.7}$
= $\frac{1}{7}$
Tick mình nha!