Maths: surds
so i'm doing surds and this question is confusing me
simplify:

now i know that i can simplify it to

and then simplify the 36 to 6 and the answer would be

but when i tried doing it with different values

and i simplify the 9 to a 3 and the 12 to

and i simplify the 4 to 2 i'm left with 3, 2 and square root 3 and i don't undertand how to get 6/3 from that

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

Mario is constructing a frame for 10 in. by 8 in. photo. he wants the frame to be the same with all the way around in the same area of the frame and photo to be 120 square inches what is the dimension of the frame?

If you measured the width of a window in inches and then in feet with measurement would you have the greater number of units