so, start floor = x
x + 7 - 9 - 4 + 8 - 2 = 14
x = 14
the elevator started on the 14th floor.
to verify: 14 + 7 = 21 - 9 = 12 - 4 = 8 + 8 = 16 - 2 = 14
Let the angle be x. the other angle is 180-x. x is twice that or x = 2(180- x)
x = 360-2x
3x =360
x =120
More information is needed to answer you.
Ok. In order to do this set up 2/5 divided by 5/7. The way you divide with fractions is by multiplying them but flipping the second fraction into 7/5 <---this is known as the reciprocal. In other words do:
2/5 x 7/5 =
14/25
There you go.