Answer:
simplify question is 3a^2 +6a+9ab
Step-by-step explanation:
Answer:
S = v1 t1 = 7 t1 traveling downstream
S = v2 t2 = 5 t2 traveling upstream
7 t1 = 5 t2
7 (6 - t2) = 5 t2 since t1 + t2 = 6
42 - 7 t2 = 5 t2
t2 = 42 / 12 = 3.5 hrs so t1 = 2.5 hrs
S = 7 t1 = 7 * 2.5 = 17.5 mi
Also, S = 5 t2 = 5 * 3.5 = 17.5 mi
Answer:
-18
Step-by-step explanation:
Answer:
45 or multiples of 45 around the centre of octagon
Step-by-step explanation:
Given that ABCDEFGH is a regular octagon. i.e. it has 8 sides.
Since regular ocagon, all interior angles would be equal.
Sum of all interior angles of octagon = 2(8)-4 right angles
= 12 right angles
Hence each angle = 12(90)/8 = 135 degrees
Thus the octagon when rotated will take the same shape if vertices interchange also due to the property that all sides and angles are equal
Since each angle is 135 imagine an octagon with one vertex at origin O, and adjacent vertex B on x axis. OB has to be coincident with BC the next side or the previous side to get it mapped onto itself
The centre will be at the middle with each side subtending an angle of 45 degrees.
Hence if rotation is done around the centre with 45 degrees we will get octagon mapped onto itself.
45, 90, 135 thus multiples of 45
