Question

B1:Tính nhanh:

a)M= -1/3 . 141/17 - 39/3 . -1/17

b)N= -9/16 . 13/3 - (-3/4)^2 . 19/3

c)P=(1+1/1.3) (1+1/2.4) (1+1/3.5)......(1+1/99.101)

B2:Tìm x,biết

a)1/2+3/2:x=1/4

b)3/4+1/4.x=7

c)1/2.4 + 1/4.6 +.........+1/(2x-2).2x = 11/48

B3:Tìm x,biết

a)(x-1/2)^2=1/81

b)x+x(1+1/x)+x(1+2/x)=1/3

c)2/x+4=3/x+5

Giải gấp hộ mk cái mấy bn ơi

Answer 1

1. a, M = -\(\dfrac{1}{3}.\dfrac{141}{17}-\dfrac{39}{3}.\left(-\dfrac{1}{17}\right)\)

= -\(\dfrac{1}{17}.\dfrac{141}{3}-\dfrac{39}{3}.\left(-\dfrac{1}{17}\right)\)

= -\(\dfrac{1}{17}\left(\dfrac{141}{3}-\dfrac{39}{3}\right)\)

= -\(\dfrac{1}{17}.34\)

= -2

@Lê Thị Hồng Ngát

Answer 2

1. b, \(\dfrac{3}{4}+\dfrac{1}{4}x=7\)

<=> \(\dfrac{1}{4}x=\dfrac{25}{4}\)

<=> x = 25

@Lê Thị Hồng Ngát

Answer 3

1. b, N = -\(\dfrac{9}{16}.\dfrac{13}{3}-\left(-\dfrac{3}{4}\right)^2.\dfrac{19}{3}\)

= -\(\dfrac{9}{16}.\dfrac{13}{3}+\dfrac{9}{16}.\dfrac{19}{3}\)

= \(\dfrac{9}{16}\left(-\dfrac{13}{3}+\dfrac{19}{3}\right)\)

= \(\dfrac{9}{16}.2\)

= \(\dfrac{9}{8}\)

@Lê Thị Hồng Ngát