Determine whether the given Lines are perpendicular

I need a fast method to do this equation

How many different ways 5 people a, b, c, d, e sit in a row in movie theater if a and b must sit together, c must sit to the right of but neceraily next to b, d and e will not sit next to each other?

What is the difference between a tax credit and a tax deduction?

Multiply 1.24 (-3.6)

Shrinking faster than any other nation's, the projected decline of Japan's population is 17 percent during the next half century.

What is the lcm for 9 12 18?

Tell whether the statement is true or false. 8 €{16, 24, 32, 40, 48} False True

What integer is the opposite of - 6? a. 1/6 b. 6 c. - 1/6 d. - 6

Anthony decided to buy two DVDs that we're not included in the deal. His price was $21.60. The sales tax is 8 percent. What was the cost of the two DVDs before the sales tax was added?

Evaluate h (0). what does this value tell you? Explain in the context of the problem

How did or do other cultures measure their years and what year is the current year for those calendars?