Question

question no 11 and 9 please help me

Answer 1

a1/ a2= b1/ b2= c1/c2
2÷k+2=3÷6=4÷3k+2
by cross multiplication
12=3k+6 ;9k+6=24
12-6=3k ;9k=24-6
6=3k ;9k= 18
2=k ; k= 2

11. sin(A-B)=1\2
sin(A-B)=sin30
(A-B)=30
A=30+B ......(i)
cos (A+B)=1/2
cos (A+B)=cos60
A+B=60
putting the value of A from i
30+B+B=60
30+2B=60
2B =60-30
2B=30
B=30÷2
B=15
A=30 +B
putting the value of B
A=30+15
A=45