m+(50+m)+3(50+m)=1,000

Solution for m+(50+m)+3(50+m)=1,000 equation:

m+(50+m)+3(50+m)=1,000

We simplify the equation to the form, which is simple to understand 
m+(50+m)+3(50+m)=1,000

Remove unnecessary parentheses
+m+50+m+3+*(+50+m+)=+1,000

Reorder the terms in parentheses
m50+m+(+150+3m)=1,000

Remove unnecessary parentheses
+m+50+m+150+3m=+1,000

We move all terms containing m to the left and all other terms to the right. 
+1m+1m+3m=+1-50-150

We simplify left and right side of the equation. 
+5m=-199

We divide both sides of the equation by 5 to get m. 
m=-39.8