Toán Tìm x: 15-2x = -77 ; -31-(-2-x) = -75 ; -15-3x = -90 ; -41-(x-51) = -72 27/11/2021 By Arianna Tìm x: 15-2x = -77 ; -31-(-2-x) = -75 ; -15-3x = -90 ; -41-(x-51) = -72
` 15-2x = -77` `⇔2x=15-(-77)` `⇔2x=92` `⇔x=92:2` `⇔x=46` Vậy `x=46` `-31-(-2-x) = -75` `⇔-31+2+x=-75` `⇔-29+x=-75` `⇔x=-75+29` `⇔x=-46` Vậy `x=-46` ` -15-3x = -90` `⇔3x=-15+90` `⇔3x=75` `⇔x=75:3` `⇔x=25` Vậy `x=25` `-41-(x-51) = -72` `⇔-41-x+51=-72` `⇔10-x=-72` `⇔x=10–72` `⇔x=82` Vậy `x=82` Trả lời
15 – 2x = -77 2x = 15 – ( -77 ) 2x = 15 + 77 2x = 92 x = 92 : 2 x = 46 Vậy x = 46 -31 – ( -2 – x ) = -75 -31 + 2 + x = -75 -29 + x = -75 x = -75 + 29 x = -75 + 29 x = -46 Vậy x = -46 -15 – 3x = -90 3x = -15 – ( -90 ) 3x = 90 – 15 3x = 75 x = 75 : 3 x = 25 Vậy x = 25 -41 – ( x – 51 ) = -72 -41 – x + 51 = -72 51 – 41 – x = -72 10 – x = -72 x = 10 – ( -72 ) x = 10 + 72 x = 82 Vậy x = 82 Trả lời
` 15-2x = -77`
`⇔2x=15-(-77)`
`⇔2x=92`
`⇔x=92:2`
`⇔x=46`
Vậy `x=46`
`-31-(-2-x) = -75`
`⇔-31+2+x=-75`
`⇔-29+x=-75`
`⇔x=-75+29`
`⇔x=-46`
Vậy `x=-46`
` -15-3x = -90`
`⇔3x=-15+90`
`⇔3x=75`
`⇔x=75:3`
`⇔x=25`
Vậy `x=25`
`-41-(x-51) = -72`
`⇔-41-x+51=-72`
`⇔10-x=-72`
`⇔x=10–72`
`⇔x=82`
Vậy `x=82`
15 – 2x = -77
2x = 15 – ( -77 )
2x = 15 + 77
2x = 92
x = 92 : 2
x = 46
Vậy x = 46
-31 – ( -2 – x ) = -75
-31 + 2 + x = -75
-29 + x = -75
x = -75 + 29
x = -75 + 29
x = -46
Vậy x = -46
-15 – 3x = -90
3x = -15 – ( -90 )
3x = 90 – 15
3x = 75
x = 75 : 3
x = 25
Vậy x = 25
-41 – ( x – 51 ) = -72
-41 – x + 51 = -72
51 – 41 – x = -72
10 – x = -72
x = 10 – ( -72 )
x = 10 + 72
x = 82
Vậy x = 82