Question

tìm x sao cho 

a ) 2x+ 3 chia hết cho x - 2 

b ) x - 6 chia hết cho x +3

Answer 1

a)<=>2(x-2)+5 chia hết x-2

=>10 chia hết x-2

=>x-2\(\in\){-1,-2,-5,-10,1,2,5,10}
=>x\(\in\){1,0,-3,-8,3,4,7,12}

b)<=>(x+3)-9 chia hết x+3

=>9 chia hết x+3

=>x+3\(\in\){-1,-3,-9,1,3,9}

=>x\(\in\){-4,-6,-12,-2,0,6}