Question 175789
{{{D=sqrt((x[1]-x[2])^2+(y[1]-y[2])^2)}}}
{{{25=sqrt((8-15)^2+(a-35)^2)}}}
{{{625=(-7)^2+(a-35)^2)}}}
{{{625=49+(a-35)^2)}}}
{{{(a-35)^2=576)}}}
{{{(a-35)^2=576)}}}
{{{a-35=0 +- 24)}}}
{{{a[1]=24+35=59}}}
{{{a[2]=-24+35=11}}}