tìm x
a, 7 . x – 8 = 0
b, ( x – 35 ) – 120 = 0
c, 124 + ( 18 – x ) = 217
d, 156 – ( x + 61 ) = 82
e, 4 . x . 17 = 0
g, ( 195 – x ) ÷ 25 = 7
h, 504 ÷ ( 16 – 3 . x ) = 72
i, 272 – ( 4 . x + 15 ) = 45
tìm x
a, 7 . x – 8 = 0
b, ( x – 35 ) – 120 = 0
c, 124 + ( 18 – x ) = 217
d, 156 – ( x + 61 ) = 82
e, 4 . x . 17 = 0
g, ( 195 – x ) ÷ 25 = 7
h, 504 ÷ ( 16 – 3 . x ) = 72
i, 272 – ( 4 . x + 15 ) = 45
Đáp án:
a,
7x – 8 = 0
⇒ 7x = 8
⇒ x = `8/7`
b,
( x – 35 ) – 120 = 0
⇒ x – 35 = 120
⇒ x = 155
c,
124 + ( 18 – x ) = 217
⇒ 124 + 18 – x = 217
⇒ 142 – x = 217
⇒ x = 142 – 217
⇒ x = -75
d,
156 – ( x + 61 ) = 82
⇒ 156 – x + 61 = 82
⇒ 217 – x = 82
⇒ x = 217 – 82 = 135
e,
4 . x . 17 = 0 ⇒ 68x = 0 ⇒ x = 0
g,
( 195 – x ) ÷ 25 = 7 ⇒ 195 – x = 175 ⇒ x = 20
h, 504 ÷ ( 16 – 3 . x ) = 72
⇒ 504 ÷ ( 16 – 3x ) = 72
⇒ 16 – 3x = 7
⇒ 3x = 9
⇒ x = 3
i, 272 – ( 4 . x + 15 ) = 45
⇒ 4x + 15 = 227⇒ 4x = 212 ⇒ x = 53
a,
`7x – 8 = 0`
`=> 7x = 8`
`=> x = 8/7`
b,
`( x – 35 ) – 120 = 0`
`=> x – 35 = 120`
`=> x = 155`
c,
`124 + ( 18 – x ) = 217`
`=>124 + 18 – x = 217`
`=> 142 – x = 217`
`=> x = 142 – 217`
`=> x = -75`
d,
`156 – ( x + 61 ) = 82`
`=> 156 – x + 61 = 82`
`=> 217 – x = 82`
`=> x = 217 – 82 = 135`
e,
`4 . x . 17 = 0`
`=>68x = 0`
`=> x = 0`
g,
`( 195 – x ) ÷ 25 = 7`
`=> 195 – x = 175`
`=> x = 20`
h,
`504 ÷ ( 16 – 3 . x ) = 72`
`=> 504 ÷ ( 16 – 3x ) = 72`
`=>16 – 3x = 7`
`=>3x = 9`
`=>x = 3`
i,
`272 – ( 4 . x + 15 ) = 45`
`=>4x + 15 = 227`
`=>4x = 212`
`=>x = 53`
#CHUC_BAN_HOC_TOT