It is given that a ⋅ b. a = 6i - 6j, b = 4i + 2j
we know that i is the unit vector along x axis
we also know that j is the unit vector along y axis
here a is given equal to 6i - 6j
here b is given 4i +2j
we have to find the dot product of a and b
therefore dot product of a and b i.e a.b = (6i - 6j).(4i + 2j)=
24 + 0 -12 - 0 = 12
therefore dot product of a and b is a.b = 12