now we have to get the w's to one side of the equation so we can solve for it. so that mean we have to subtract 2w from both sides. 2w - 2w is 0. and then 4w - 2w = 2w. so now we have
-8 = 2w - 7
then to slowly start isolating w, add 7 to both sides of th equation. so now its
-1 = 2w
finally to get w by itself divide 2 from both sides.
For a glider, which a paper airplane is the more lift the glider has the longer it can fly. However, you must keep the weight and drag in check to avoid flight failure.