Question

x+2/11+x+2/12+x+2/13=x+2/14+x+2/15

Answer 1

x+2/11+x+2/12+x+2/13=x+2/14+x+2/15

3x+(2/11+2/12+2/13)=2x+(2/14+2/15)

3x+431/858=2x+29/105

3x-2x=29/105-431/858

x=-6791/30030

Answer 2

 (x+2)/11+(x+2)/12+(x+2)/13=(x+2)/14+(x+2... 
<=> (x+2)/11+(x+2)/12+(x+2)/13 - (x+2)/14 - (x+2)/15 - (x+2)/16 = 0 
<=> (x+2)(1/11+1/12+1/13 - 1/14 - 1/15 - 1/16) = 0 
vì: (1/11+1/12+1/13 - 1/14 - 1/15 - 1/16) khác 0 nên x-2 = 0 hay x=2