Convert y = 2x + 6 to standard form. 1- 2x +y = 3
2- x+ 1/2y = 3
3- 2x - y = -6
4- -2x +y= 6

1) 2/5

2) zero=0/1

3) zero=0/2

4) -4/5

5) undefined=3/0

to complete this square you have to rotate about the origin 270 degrees clockwise.

answer: 4  

the square root of 16 is 4. it is a very simple mathematic concept. a square root when a number multiplied by itself will result in a number. here, the number 16 comes when 4 is multiplied by 4. hence the square root of 16 is 4. you can always figure out a square root by the inverse operation of squaring.  

54/3 is 18 so 18 is your answer