How to expand :

-2(t+1)^2+5

Please provide a step by step explanation!!

What is the slope of the line that contains the points (4,8) and (9,8)? what type of line is it?

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

Which statements are true? check all that apply. the line x = 0 is perpendicular to the line y = –3. all lines that are parallel to the y-axis are vertical lines. all lines that are perpendicular to the x-axis have a slope of 0. the equation of the line parallel to the x-axis that passes through the point (2, –6) is x = 2. the equation of the line perpendicular to the y-axis that passes through the point (–5, 1) is y = 1.