Prove equality of triangles

Line l passes through points (0,4) and (3,6) what is the slope of a line that is parallel to line l -2/3 -3/2 2/3 3/2

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.

What is the number 321,000,000 in scientific notation? also what is the number? ?