Help with force question? i dont know how to get the right answer?

[snash1057]

Two lifeguards pull on ropes attached to a raft. If they pull in the same direction, the raft experiences a net external force of 304 N to the right. If they pull in opposite directions, the raft experiences a net external force of 115 N to the left.

Find the force exerted by each lifeguard on the raft. (Disregard any other forces acting on the raft.)
____N( larger force)
____N( smaller force)



ive set it up at F1 + F2 = 304 and F1 - F2 = -115 , but i don't know what to do with that, how am i supposed to find the forces? i feel like I am just forgetting a simple math tool haha

 

[rock.freak667]

ive set it up at F1 + F2 = 304 and F1 - F2 = -115 , but i don't know what to do with that, how am i supposed to find the forces? i feel like I am just forgetting a simple math tool haha

So let's call

F₁+F₂=304 ...eq'n 1

F₁-F₂=115...eq'2

What happens if we add eq'n 1 to eq'n 2 ?