\(F1=100i-120j+75k\)
\(F2=-200i+250j+100k\)
\(RA=4i+5j+3k\)
\(RB=4i+5j+3k\)
\(F1\ X\ RB\ \)
\(i\ \ \ \ \ \ \ \ \ j\ \ \ \ \ \ \ \ \ k\)
\(4\ \ \ \ \ \ \ \ \ 5\ \ \ \ \ \ \ \ \ 3\)
\(100\ -120\ \ \ 75\)
\(i\left(5\left(75\right)-\left(-120\right)\left(3\right)\right)-j\left(\left(4\right)\left(75\right)-\left(100\right)\left(3\right)\right)+k\left(\left(4\right)\left(-120\right)-\left(100\right)\left(5\right)\right)\)
\(i\left(375+360\right)-j\left(300-300\right)+k\left(-480-500\right)\) \(=735i-980k\)
\(F2\ X\ RA\)
\(\ \ \ \ \ i\ \ \ \ \ \ \ \ \ j\ \ \ \ \ \ \ \ k\)
\(\ \ \ \ \ 4\ \ \ \ \ \ \ \ 5\ \ \ \ \ \ \ \ \ 3\)
\(-200\ \ \ \ 250\ \ \ \ 100\)
\(i\left(\left(5\right)\left(100\right)-\left(250\right)\left(3\right)\right)\)\(\)\(-j\left(\left(4\right)\left(100\right)-\left(-200\right)\left(3\right)\right)+k\left(\left(4\right)\left(250\right)-\left(-200\right)\left(5\right)\right)\)
\(i\left(500-750\right)-j\left(400+600\right)+k\left(1000+1000\right)\)
\(=-250i-1000j+2000k\)
SUMA TOTAL (FT)
\(FT=735i-980k-250i-1000j+2000k\)
\(FT=485i-1000j+1020k\)
\(\)