How do you write 100 as a power of 10

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Which is a true statement comparing the graphs of x^2/6^2-y^2/8^2 = 1 and x^2/8^2-y^2/6^2 the foci of both graphs are the same points. the lengths of both transverse axes are the same. the directrices of = 1 are horizontal while the directrices of = 1 are vertical. the vertices of = 1 are on the y-axis while the vertices of = 1 are on the x-axis.

Which of the following is an equation of a line parallel to the equation y=4x+1?