book Maths Puzzle Numerical Ability

okay i dont know how to do the whole typy in htingy but it says
"the square root of x+2 = the square root of 3x-6 so is it 4?

Read Solution (Total 0)

book Other Question

A plane is traveling at 500mph LA to Chicago. There are 600 miles before they land and the traffic controller comes on the radio and tells the pilot that he will not be able to giv The sides of a square measure 7 feet. How long is the diagonal?

9.9 ft
9.7 ft
11.2 ft
10.3 ft

I dont need the answer, I just would like an explanation on how to solve this.