Question 1012670
DC=AB
1.{{{6x+y=25}}}
BC=AD
2.{{{3x+2y=14}}}
Multiply eq. 2 by 2 and subtract eq. 1 from it,
{{{6x+4y-(6x+y)=28-25}}}
{{{6x+4y-6x-y=3}}}
{{{3y=3}}}
{{{y=1}}}
Then,
{{{6x+1=25}}}
{{{6x=24}}}
{{{x=4}}}