C-12-Q069mediumsingle_mcq−(a⃗+b⃗)=-(\vec{a}+\vec{b})=−(a+b)=a−a⃗+b⃗-\vec{a}+\vec{b}−a+bba⃗−b⃗\vec{a}-\vec{b}a−bc−a⃗−b⃗-\vec{a}-\vec{b}−a−bda⃗+b⃗\vec{a}+\vec{b}a+b