Question 973400
Equate the corresponding parts, because similarity allows it.  This means identifying which parts correspond.


{{{system(4x-10=75,x+5=30)}}}, which is two different equations, but since this pair of similar triangles gives this system, you MUST expect both solutions for x to be equal.  NO OTHER POSSIBILITY, unless labeled sides are done wrong.


4x=75+10
4x=85
x=85/4

-


x+5=30
x=30-5
x=25


No good!  {{{x=85/4<>25}}}.
Either incorrect information given or the triangles are not similar.