I think you're having trouble because the equation you wrote for 8a has a slight typo.
The question says that the length is 9 less than twice the width. Your equation states the length is 9 times the width minus 2. So the length actually equals 2w – 9, meaning that w(2w – 9) = 180
Hope this helps! If you're still having trouble, let me know :)
#7
2,4,8,16
15,30,60,120
#9
1,2,3,
4,8,12
2(10+5)−5
=(2)(15)−5
=30−5
=25
C is the answer.
A rectangle is considered a special case of a parallelogram because: Aparallelogram is a quadrilateral with 2 pairs of opposite, equal and parallel sides. Arectangle is a quadrilateral with 2 pairs of opposite, equal and parallel sides BUT ALSO forms right angles between adjacent sides.