Simplify
`(b^(2)+3b-28)/(b^(2)+4b+4)÷(b^(2)-49)/(b^(2)-5b-14)`

Simplify : (2a+3b+4c) ( 4a^(2) + 9b^(2) + 16c^(2) -6ab - 12bc - 8ca )

If (log)_(10)2=a ,(log)_(10)3=bt h e n(log)_(0. 72)(9. 6) in terms of a and b is equal to (a) (2a+3b-1)/(5a+b-2) (b) (5a+b-1)/(3a+2b-2) (c) (3a+b-2)/(2a+3b-1) (d) (2a+5b-2)/(3a+b-1)

If a^(2)+b^(2)+c^(2)=1 where, a,b, cin R , then the maximum value of (4a-3b)^(2) + (5b-4c)^(2)+(3c-5a)^(2) is