What is the missing reason in the proof?
prove –(–y – x) – x = y
–(–y – x) – x = –[–y +(–x)] – x
definition of subtraction
–[–y +(–x)] – x = y + x – x
opposite of a sum property
y + x – x = y + x + (–x)
definition of subtraction
y + x + (–x) = y + [x + (–x)]
associative property of addition
y + [x + (–x)] = y + 0
additive inverse property
y + 0 = y
(blank)
answer options for (blank):
a. symmetric property
b. additive inverse property
c. additive identity property
d. opposite of a sum property

Option C is correct.

Step-by-step explanation:

The last step is y+0 =y

This represents additive identity property.

This property states if zero is added to any number we get the same number.i.e if 0 is added to y then we get y (y+0=y)

So, Option C is correct

9.55 degrees.

step-by-step explanation:

the given angle is

1 cycle is equal to 2π radians. so 4π will be equal to two cycles.

5.166667π-4π = 1.166667π

hence, this angle goes a little more than negative x axis.

1.166667π-π= 0.166667π

hence, the reference angle is 0.166667π radians.

1 radian = 57.2958 degrees

now, in degrees, this should be equals to 9.55 degrees.

yes

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step-by-step explanation: