Tìm x ∈ Z biết
a)-x+8=-7
b)-148-2x=-260
c)12x+450=15x-162
d)-/x-5/=-7
e)(x-2).(5-x)=0
g)x^3=-64
h)(x-1)^5=-32
i)-(x+1)^2+81=0
Tìm x ∈ Z biết
a)-x+8=-7
b)-148-2x=-260
c)12x+450=15x-162
d)-/x-5/=-7
e)(x-2).(5-x)=0
g)x^3=-64
h)(x-1)^5=-32
i)-(x+1)^2+81=0
$a, -x+8=-7$
$⇔-x=-7-8$
$⇔-x=-15$
$⇔x=15$
$b, -148-2x=-260$
$⇔-2x=-260+148$
$⇔-2x=-112$
$⇔x=56$
$c, 12x+450=15x-162$
$⇔12x-15x=-162-450$
$⇔-3x=-612$
$⇔x=204$
$d, \left \{ {{-(x-5)=-7} \atop {-(5-x)=-7}} \right.$
$⇔\left \{ {{-x+5=-7} \atop {-5+x=-7}} \right.$
$⇔\left \{ {{-x=-12} \atop {x=-7+5}} \right.$
$⇔\left \{ {{x=12} \atop {x=-2}} \right.$
$e, (x-2)(5-x)=0$
$⇔\left \{ {{x-2=0} \atop {5-x=0}} \right.$
$⇔\left \{ {{x=2} \atop {x=5}} \right.$
$g, x³=-64$
$⇔x³=-4³$
$⇔x=-4$
$h, (x-1)^5=-32$
$⇔(x-1)^5=-2^5$
$⇔x-1=-2$
$⇔x=-2+1$
$⇔x=-1$
$i, -(x+1)²+81=0$
$⇔-(x+1)²=-81$
$⇔\left \{ {{x+1=9} \atop {x+1=-9}} \right.$
$⇔\left \{ {{x=8} \atop {x=-10}} \right.$
a) -x+8=-7
-x=-7-8
-x=-15
x=15
Vậy x=15
b)-148-2x=-260
-2x=-260+148
-2x=-112
x=-112/(-2)
x=56
Vậy….
c)12x+450=15x-16
12x-15x=-16-450
-3x=-466
x=-466/(-3)
x=466/3
Vậy…
d) -/x-5/=-7
=>x-5=7
=>x=7+5
=>x=12
Vậy…
e)(x-2).(5-x)=0
=>x-2=0 hoặc 5-x=0
x=0+2 x=5-0
x=2 x=5
Vậy….
g) x³=-64
=>x=-4
Vậy….
h)(x-1)^5=-32
=>x-1=2
=>x=3
Vậy….
i)-(x+1)^2+81=0
-(x+1)^2=-81
=>x+1=9 hoặc x+1=-9
x=8 x=-10
Vậy…
Chúc bn hc tốt, cho mk 5 sao và ctlhn nha^^