Question

Billy weighs 50lbs less then his brother together they weigh 210lbs what is the equation to figure out how much billy weighs

Answer 1

Let's say B stands for Billy and Z stands for his brother

B+Z=210 if so we divide 210 in half
210/2=(105+50)+(105-50)=210
Now you can solve the rest.
I hope this is right :)