A X : 0,25 + X : 0,125 -X : 0,1 = 12,4
B X x 16 – X x 13 +X =500
C 125 : X + 375 : X – 200 : X = 12
D X +25% x X =8
E X x 4 + 20% x X = 44,1
G 13 + X
———- = 5/9
36
A X : 0,25 + X : 0,125 -X : 0,1 = 12,4 B X x 16 – X x 13 +X =500 C 125 : X + 375 : X – 200 : X = 12 D X +25% x X =8 E X x 4 + 20% x X = 44,1 G 13
By Margaret
`text{promax123}`
Đáp án :
a)
X : 0,25 + X : 0,125 – X : 0,1 = 12,4
X : `25/100` + X : `125/1000` – X : `1/10` = 12,4
X x 4 + X x 8 – X x 10 = 12,4
X x ( 4 + 8 – 10 ) = 12,4
X x 2 = 12,4
X = 12,4 : 2
X = 6,2
——————————————————–
b)
X x 16 – X x 13 + X = 500
X x 16 – X x 13 + X x 1 = 500
X x ( 16 – 13 + 1 ) = 500
X x 4 = 500
X = 500 : 4
X = 125
——————————————————–
c)
125 : X + 375 : X – 200 : X = 12
( 125 + 375 – 200 ) : X = 12
300 : X = 12
X = 300 : 12
X = 25
——————————————————–
d)
X + 25% x X = 8
X x 1 + `25/100` x X = 8
X x 1 + 0,25 x X = 8
X x ( 1 + 0,25 ) = 8
X x 1,25 = 8
X = 8 : 1,25
X = 6,4
——————————————————–
e)
X x 4 + 20% x X = 44,1
X x 4 + `20/100` x X = 44,1
X x 4 + 0,2 x X = 44,1
X x ( 4 + 0,2 ) = 44,1
X x 4,2 = 44,1
X = 44,1 : 4,2
X = 10,5
——————————————————–
g)
13 + X
———- = `5/9`
36
13 + X = `5/9` x 36
13 + X = 20
X = 20 – 13
X = 7
`a,`
`x : 0,25 + x : 0,125 – x : 0,1 = 12,4`
`x × 4 + x × 8 – x × 10 = 12,4`
`x × (4 + 8 – 10) = 12,4`
`x × 2 = 12,4`
`x = 12,4 : 2`
`x = 6,2`
`b,`
`x × 16 – x × 13 + x = 500`
`x × (16 – 13 + 1) = 500`
`x × 4 = 500`
`x = 500 : 4`
`x = 125`
`c,`
`125 : x + 375 : x – 200 : x = 12`
`125 × 1/x + 375 × 1/x – 200 × 1/x = 12`
`(125 + 375 – 200) × 1/x = 12`
`300 × 1/x = 12`
`1/x = 12 : 300`
`1/x = 1/25`
`x = 25`
`d,`
`x + 25% × x = 8`
`x × (1 + 25%) = 8`
`x × (1 + 0,25) = 8`
`x × 1,25 = 8`
`x = 8 : 1,25`
`x = 6,4`
`e,`
`x × 4 + 20% × x = 44,1`
`x × 4 + 0,2 × x = 44,1`
`x × (4 + 0,2) = 44,1`
`x × 4,2 = 44,1`
`x = 44,1 : 4,2`
`x = 10,5`
`g,`
`(13 + x)/36 = 5/9`
`(13 + x)/36 = 20/36`
`13 + x = 20`
`x = 20 – 13`
`x = 7`