eww...vectors...

here's the problem:

**The magnitude and direction of two forces acting on an oject are **

-70 lbs, S56[degree]E and

-50 lbs, N72[degree]E.

find the magnitude, to the nearest hundredth of a pound, and the direction angle, to the nearest tenth of a degree, of the resultant force.

i did this problem like 5 times! i keep getting different answers.

the answer in the back of the book is **108.21 lbs, S77.4[degree]E**.

could someone explain it to me?

tthhhaannnk you, even for reading my post. thanks.