Tell whether the lines for each pair of equations are parallel, perpendicular, or neither. y =-7/2x - 9 -14x - 4y = -20

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.  

all of the measures need to be converted to the same measure; such as inches. if you do that it is easy to determine which is the longest, 2500 mm which is approximately 97.5 inches.

no solution exists the way you wrote the equation.