1114/7

A=1/1.2+1/3.4+1/5.6+.........+1/99.100

1/7 . 7/3 + 5/2 . 3/7 . 59/6 . 1/7

= 1/7 . (7/3 + 5/3 . 3/7 . 59/6)

= 1/7 . 131/14

=   131/98

ket qua la 131/98

Vãi thánh ! BÀi dễ ợt mà cũng đăng 

\(2x\left(9:6-7.43+x\right)\)

\(=2x\left(x-301+\frac{3}{2}\right)\)

\(=2x\left(x-\frac{602}{2}+\frac{3}{2}\right)\)

\(=2x\left(x-\frac{599}{2}\right)\)

a)-35.12-8-35=-35(12+8)=-35.20=-700

b)23.(-7)-7.5+(-18).7=-7(23+59+18)=-7.100=-700

c)115-(-12+29)=115+12-29=98

d)\(3\left(-7\right)^2+5\left(-4\right)^3=3.7^2-5.4^3=3.49-5.64=147-320-173\)

\(a,-35.12-8.35\)

\(=\left(-35\right)\left(12+8\right)\)

\(=-700\)

\(b,-23.7-7.59-18.7\)

\(=7\left(-23-59-18\right)\)

\(7.\left(-100\right)=-700\)

\(b,115-\left(-12+29\right)\)

\(=115+12-29\)

\(=98\)

\(c,3.\left(-7\right)^2+5.\left(-4\right)^3\)

\(=3.49-5.64\)

\(=147-320\)

\(=-173\)

Giúp mình vs

(-6.37 * 0.4)*2.5= -2.548*2.5=-6.37

an may di bn ko thi nhan don vs da thuc

a) n = 14             

b) n = 2 

c) n = 4   

d) n = 8

e) n = 2

f) n = 5

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