s=3i−j;t=2i+3js = 3i - j; t = 2i + 3js=3i−j;t=2i+3j
t−3s=(2i+3j)−3(3i−j)=2i+3j−9i+3j=−7i+6jt - 3s = (2i + 3j) - 3(3i - j) = 2i + 3j - 9i + 3j = -7i + 6jt−3s=(2i+3j)−3(3i−j)=2i+3j−9i+3j=−7i+6j
t+3s=(2i+3j)+3(3i−j)=2i+3j+9i−3j=11it + 3s = (2i + 3j) + 3(3i - j) = 2i + 3j + 9i - 3j = 11it+3s=(2i+3j)+3(3i−j)=2i+3j+9i−3j=11i
(t−3s).(t+3s)=(−7i+6j).(11i)=−77(t - 3s).(t + 3s) = (-7i + 6j).(11i) = -77(t−3s).(t+3s)=(−7i+6j).(11i)=−77
