Question 75178
Perform the indicated operations:
3 squared [48] + 7 squared [12] - squared symbol [75] 
----------------
I think the check mark is the symbol for "square root".
So your problem is :
3sqrt(48) + 7sqrt(12) - sqrt(75)
=3sqrt(16*3)+7sqrt(4*3) - sqrt(25*3)
=3*4sqrt3 + 7*2sqrt3 - 5sqrt3
= 12sqrt3 + 14sqrt3 -5sqrt3
=21sqrt3
===============
Cheers,
Stan H.