a: \(\Leftrightarrow5^{10}⋮5^{2x}\)
\(\Leftrightarrow2x\in\left\{1;2;5;10\right\}\)
hay \(x\in\left\{\dfrac{1}{2};1;\dfrac{5}{2};5\right\}\)
b: \(\Leftrightarrow\left(2x-1;y-2\right)\in\left\{\left(1;35\right);\left(5;7\right);\left(7;5\right);\left(35;1\right)\right\}\)
hay \(\left(x,y\right)\in\left\{\left(1;37\right);\left(3;9\right);\left(4;7\right);\left(18;3\right)\right\}\)
Tim x,y thuoc N:
(y - 2)(2x - 1) = 35
P/s: nhung ban nao chac chan thi
lam nghen
Thanks truoc 
tim min(x+y)^2+(x+1)^2+(y-2)^2
CM bieu thuc sau khong phu thuoc vao x
a) x .(y+z-yz) - y.(z+x-xz) + z.(y-x)
b) ( x+1) . \(\left(1+x-x^2+x^3-x^4\right)-\left(x-1\right).\left(1+x+x^2+x^3+x^4\right)+2x^5-2x\)
Tim cap (x,y) thoa man
( x-y+2) . ( x-2) + ( x-y+2) . ( 2-x) =5
tim x: a.4/(x^2+2x+1)+3/(x^2+2x+3)=3/2
b.4x/(x^2+4x+5)+7x/(x^2-4x+5)=39/10
tim x
a, (2x-1)*(x+3)-(x+2)2-x*(x+1)=2
b,(x-5)2-1/4*(x-1)2=0
bai1.tim x biet:
a,(x+2).(x+3)-(x-2).(x+5)=0
b,(2x+3).(x-4)+(x-5).(x-2)=(3x-5).(x-4)
c,(8x-3).(3x+2)-(4x+7).(x+4)=(2x+1).(5x-1)=33
tim cap (x,y ) thoa man
\(x^2.\left(x+3\right)+y^2.\left(y+5\right)-\left(x+y\right).\left(x^2-xy+y^2\right)=0\)
1 . Phan tich da thuc thanh nhan tu :
x^2 + 6x - 9 -y^2
2. Tim x :
x^2 -x - 12 = 0
