Resolver ecuaciones matemáticamente

Respuesta:

[500-10(X-50)](x-40)=9000

[500-10X 500](X-40 )=9000

(1000-10X)(X-40)=9000

10(100-X)(X-40)=9000

( 100-X)(X-40)=900

X?-140X 4000=-900

X?-140X 4900=0

(X- 70)?=0

X=70.