Question

Tìm x

a) -1/2 . x = 5

b) x-1/9 = 8/3

c) x + 5/6 = 16/42 - -8/56

d) 1 3/4x - 5 = -3 1/3

e) 3 1/3 - 3/4 : x = -1/6

g) 3/x + 5 = 15%

h) 1/2 + 1/2.3 + 1/3.4 +...+1/x(x+1) = 49/50

Answer 1

a: x=5:(-1/2)=-10

b: x=8/3+1/9=25/9

c: =>x+5/6=11/21

=>x=-13/42

d: =>7/4x-5=-10/3

=>7/4x=5/3

=>x=20/21

e: =>10/3-3/4:x=-1/6

=>3/4:x=10/3+1/6=21/6=7/2

=>x=3/4:7/2=3/4*2/7=6/28=3/14

g: =>3/(x+5)=3/20

=>x+5=20

=>x=15

h: =>1-1/2+1/2-1/3+...+1/x-1/x+1=49/50

=>1-1/x+1=49/50

=>x+1=50

=>x=49