Tìm số nguyên x, biết:
a) 2x – (–17) = 15
b) x – 2 = -3.
c) 2x + 12 = 3(x – 7)
d) 2. ( x – 3) – 3. (x – 5) = 4. ( 3 – x) – 18
e) – 2(2x – 8) + 3(4 – 2x) = -72 – 5(3x – 7)
Tìm số nguyên x, biết:
a) 2x – (–17) = 15
b) x – 2 = -3.
c) 2x + 12 = 3(x – 7)
d) 2. ( x – 3) – 3. (x – 5) = 4. ( 3 – x) – 18
e) – 2(2x – 8) + 3(4 – 2x) = -72 – 5(3x – 7)
`a) 2x – (–17) = 15`
`=>2x+17=15`
`=>2x=15-17`
`=>2x=-2`
`=>x=-1` `text((số nguyên âm))`
`b)x-2=-3`
`=>x=-3+2`
`=>x=-1` `text((số nguyên âm))`
`c)2x+12=3(x-7)`
`=>2x+12=3x-21`
`=>2x-3x=-21-12`
`=>-x=-33`
`=>x=33` `text((số nguyên dương))`
`d)2(x-3)-3(x-5)=4(3-x)-18`
`=>2x-6-3x+15=12-4x-18`
`=>-x+9=-4x-6`
`=>-x+4x=-6-9`
`=>3x=-15`
`=>x=-5` `text((số nguyên âm))`
`e)– 2(2x – 8) + 3(4 – 2x) = -72 – 5(3x – 7)`
`=>-4x+16+12-6x=-72-15x+35`
`=>-4x-6x+15x=-72+35-12-16`
`=>5x=-65`
`=>x=-13` `text((số nguyên âm))`
$@FBoy24$
`a)` `2x-(-17)=15`
`<=>2x+17=15`
`<=>2x=15-17`
`<=>2x=-2`
`<=>x=-1` ( `-1` là số nguyên âm )
Vậy `x=-1`
`b)` `x-2=-3`
`<=>x=-3+2`
`<=>x=-1` ( `-1` là số nguyên âm )
Vậy `x=-1`
`b)` `2x+12=3(x-7)`
`<=>2x+12=3x-21`
`<=>2x-3x=-21-12`
`<=>-x=-33`
`<=>x=33` ( `33` là số nguyên dương )
Vậy `x=33`
`d)` `2(x-3)-3(x-5)=4(3-x)-18`
`<=>2x-6-3x+15=12-4x-18`
`<=>-x+9=-6-4x`
`<=>-x+4x=-6-9`
`<=>3x=-15`
`<=>x=-5` ( `-5` là số nguyên âm )
Vậy `x=-5`
`e)` `-2(2x-8)+3(4-2x)=-72-5(3x-7)`
`<=>-4x+16+12-6x=-72-15x+35`
`<=>-10x+28=-15x-37`
`<=>-10x+15x=-37-28`
`<=>5x=-65`
`<=>x=-13` ( `-13` là số nguyên âm )
Vậy `x=-13`