x^2-14x=-42 halve the linear coefficient, square it, add it to both sides, in this case: (14/2)^2=7^2=49, add 49 to both sides
x^2-14x+49=7 now the left side is a perfect square...
(x-7)^2=7 take the square root of both sides
x-7=±√7 add 7 to both sides
x=7±√7
The above is the two solutions, 7+√7 and 7-√7
I am not sure what they mean by the proper form other than perhaps the point when you have a complete square as in the point in the process where you have a perfect square...
The lower value is 15,The upper value is 100, The median is 32 and 39, The lower quartile is 30, the upper quartile is 50, and the interquartile range is 36.
