How do you write 8.99 x 104 in standard form?

Will give brainliest series to sigma notation write the following series in sigma notation. 6+10+14+18+22+26+30 example image shown below.

Aperpendicular bisector, cd is drawn through point con ab if the coordinates of point a are (-3, 2) and the coordinates of point b are (7,6), the x-intercept of cd is point lies on cd.

Mackenzie needs to determine whether the rectangles are proportional. which process could she use? check all that apply.