√9a^2 + √49b - a + √b a. 2b + 8 √a b. 2a - 8 √b c. 2a + 8 √b

The correct

Explanation:

Assuming you mean:

" √(9a²)  +  (√49b)  −  a  +  √b " ;

Simplify the expression:


Note that:  " √(9a²) = 3a " ;

                   "√(49b) = 7√b " ;   

And we write the expression

   →  " 3a  +  7√b  −  a  + √b " ; 

Combine the "like terms:

   " + 3a − a  =  2a " ;

   " +  7√b  +  1√b   =  8√b " ; 

Rewrite:  

    " 2a  +  8√b " ;  which is:  Answer choice:  [C]:  " 2a  +  8√b " .

The answer is $9.90 with rounding to the nearest tenth