a) x2 - 15 = 21
=> x2 = 21 + 15
=> x2 = 36
=> x2 = 62
=> x = 6
b) x3 = -8
=> x3 = -23
=> x = - 2
c) 25 - (x + 3)2 = 9
=> (x + 3)2 = 25 - 9
=> (x + 3)2 = 16
=> (x + 3)2 = 42
=> x + 3 = 4
=> x = 1
a)x^2-15=21
x^2 =21+15
x^2 =36
=>x^2=(-6)^2 hoặc x^2=6^2
+)x^2=(-6)^2 +)x^2=6^2
x =-6 x =6
b)x^3=-8 c)25-(x+3)^2=9
x^3=(-2)^3 (x+3)^2=25-9
x =-2 (x+3)^2=16=>(x+3)^2=4^2 hoặc (x+3)^2=(-4)^2
+)(x+3)^2=4^2 +)(x+3)^2=(-4)^2
x+3 =4 x+3 =-4
x =4-3 x =-4-3
x =1 x =-7
Tim so nguyen x,y biet
a) (x+5) mu 2 + (2y - 8 ) mu 2 = 0
b)(x + 3).(2y - 1 ) = 5
Tim X
3) -12 + (2x – 9) + x= 0
4) 11 + (15 - x) = 1
5) 4 - (27 - 3) = x - (13 - 4)
6) 8 - (x - 10) = 23 - (- 4 +12)
7) 105 – 5(10 – 5x) = -20
8) (x -1)(8-2x)(3x+123) = 0
9) (x2 - 25)(x+ 10) = 0
10) x(x2+5) =
Tim cac so nguyen x,y biet:a)*x2 -3*x+1 chia het cho x+2 b)x2-xy = 5x-4y-9 c) (x2-8)*(x2-15)<0 d) (x+1)2+(y+1)2+(x-y)2=2 e) (x2-4)x2>0 ai lam truoc minh tick,mai minh di hoc rui,lam giup minh di pls Thank ban truoc ne ;(
cau 1.tim x
a)15-|x-4|=6
b)-30+|25-x|=-1
c)x-(12-25)=-8
d) (x-29)-(17-38)=-9
cau 2.tim so nguyen x
a,22-(-x)=12
b,(x+5)+(x-9)=x+2
c,(27-x)+(15+x)=x-24
tim so nguyen x
(3x+9).(3x-6)=0(2x+15)-25=47-(10-x)30(x=2)-6(x-5)-24x=100/4-3x/=8/2x-5/=13/7x+3/=66tim so nguyen x, biet
a, 3-[17-x] = 289-[36+289]
b,25-[x+5]=-415-[15-415]
tim so nguyen x
(3x - 25) - (x - 9) = 2 - x
2x + (-73 - 120) - (20 - 120) = 5
Tim so nguyen x biet:
a, 82-(15+x)=72
b,(x-9).(x+2)=0
Tim so nguyen x bt
(x - 9 ) . (x + 2 ) = 0
Tim so nguyen n sao cho 2n - 1 là bội của n + 3