Chapter 2 - Force Vectors - Section 2.4 - Addition of a System of Coplanar Forces - Problems - Page 41: 42

$F_{1} = (680\hat{i} - 510\hat{j})N$ $F_{2} = (-312\hat{i} - 541\hat{j})N$ $F_{3} = (-530\hat{i} - 530\hat{j})N$

$F_{1} =(4/5 \times 850 \hat{i} - 3/5 \times 850 \hat {j})= (680\hat i - 510\hat j)N$ $F_{2} =(-625 \times \sin 30 ° \hat i -625 \times \cos 30 ° \hat j)= (-312\hat i - 541\hat j)N$ $F_{3} =(-750 \times \sin 45 ° \hat i + 750 \times \cos 45 ° \hat j)= (-530\hat i - 530\hat j)N$