tim x biet
1+ -1/60 + 19/120 < x/30<58/90+59/72+ -1/60
Tim x biet
\(1+\frac{-1}{60}+\frac{19}{120}< \frac{x}{36}< \frac{58}{90}+\frac{59}{72}+\frac{-1}{60}\)
\(1+\frac{-1}{60}+\frac{19}{120}< \frac{x}{36}< \frac{58}{90}+\frac{59}{72}+\frac{-1}{60}\)
=> \(\frac{137}{120}< \frac{x}{36}< \frac{521}{360}\)
=> \(\frac{411}{360}< \frac{10x}{360}< \frac{521}{360}\)
=> 411 < 10x < 521
=> x \(\in\){ 42,43,44,...,52}
TIM x THUOC Z , BIET :
a) / 2x + 1 / = 7
b) 3/x + 1 / + 1 = 27
c) 20 = 20 + 19 + 18 + 17 + ..... + x
d) x + ( x+ 1 ) + ( x + 2 + ...... + 29 + 30 = 30
a) / 2x + 1 / = 7
=>2x+1 thuộc {-7;7}
+)2x+1=7=>2x=6=>x=3
+)2x+1=-7=>2x=-8=>x=-4
vậy x thuộc {3;-4}
b) 3/x + 1 / + 1 = 27
=>3/x+1/=27-1=26
=>/x+1/=26:3=26/3
=>x+1 thuộc {-26/3; 26/3}
+)x+1=26/3=>x=26/3 - 1 = 23/3
+)x+1=-26/3=>x=-26/3 - 1=-29/3
vậy x thuộc {-29/3; 23/3}
bài 1 rút gọn phân số sau
a -1/4+33/44
b -2/7+1/2+-3/4
Bai 2 tim x
1+-1/60+19/120<x/36<58/99+59/72+-1/60
tìm x thuộc z biết 1 + 1/60 + 19/120 < x/36 + -1/60 < 58/90 + 59/72 + -1/60
tìm x, biết: 1+-1/60+19/120<x/36<58/90+59/72+-1/60
Tìm x biết : 1+-1/60+19/120<x/36<58/90+59/72+-1/60
tìm x biết :
1+\(\dfrac{-1}{60}\)+\(\dfrac{19}{120}\)<\(\dfrac{x}{36}\)<\(\dfrac{58}{90}\)+\(\dfrac{59}{72}\)+\(\dfrac{-1}{60}\)
Tìm x thuộc z ,biết:
1+ -1/60+19/120<x/36+ -1/60<58/90+59/72+ -1/60
tìm x biết
1+ -1/60+19/120<x/36<58/90+59/72+ -1/60