Question

Given |a1|=2 and |b2|=3 and |a1+a2|=3, find the values of (a1+2a2).(3a1-4a2)​

Answer 1

a1+2a2=3

2a2=3-a1

a2=(3-a1)/2

put the values in given Eq

2+(3-2) * 3*2- 4*(3-2)/2

3*6-2

18-2

16