<span>There is not a property of "1" for addition, but the identity property in this case uses "0" instead. If a number is increased by 1, the value will necessary be increased or decreased by the amount added or subtracted. However, if the number either adds or subtracts zero, then value will be left unchanged. Examples: 3+1 = 4, but 3+0 = 3,</span>
Add them then take away 20
Step-by-step explanation:
xy + 10 = 0. => y = -10/x.
2x + 3y = 7. => 3y = -2x + 7, y = -2/3 x + 7/3.
When -10/x = -2/3 x + 7/3,
-10 = -2/3 x² + 7/3 x, 2/3 x² - 7/3 x - 10 = 0.
=> 2x² - 7x - 30 = 0
=> (2x + 5)(x - 6) = 0
=> x = -2.5 or x = 6.
dy/dx = d/dx [-10/x] = 10/x².
When x = -2.5, dy/dx = 10 / (-2.5)² = 1.6.
When x = 6, dy/dx = 10 / (6)² = 5/18.
Hence the gradients at the points are 1.6 and 5/18.
Just add 360 to -800 until you end up with an angle between 0 and 360:
-800+360=-440
-440+360=-80
-80+360=280
So the angle is 280 degrees.
