Wonderful! The method is simple. You must just add the x- and y-components of $$\vec{A}$$ and $$\vec{B}$$ and subtract those of $$\vec{C}$$ from this sum. So, the x-component will be $$5+3-2$$ and the y-component will be $$4+7-12$$.
$$\vec{A} = A_x \hat{i} + A_y \hat{j}$$,
$$3 \vec{A} = 3 A_x \hat{i} + 3 A_y \hat{j}$$
If $$\vec{A} = 3 \hat{i} - 2 \hat{j}$$, what is $$5 \vec{A}$$?
• $$15 \hat{i} + 10 \hat{j}$$
• $$10 \hat{i} + 15 \hat{j}$$
• $$15 \hat{i} - 10 \hat{j}$$
• $$10 \hat{i} - 15 \hat{j}$$