I'm assuming you mean triangle angles?
If so, all angles add up to 180 so combine them and set them equal to 180.
51+82+5x+2=180
135+5x=180
5x=45
x=9
Answer: Choice C) Multiplication property of inequalityThe rule basically says that if you start with a < b and you multiply both sides by some positive number c, then a*c < b*c. The sign doesn't flip if you multiply both sides by a positive number.
The sign will flip if c is negative. So we'll go from a < b to a*c > b*c if c is negative.
Example 1:
1 < 5
-2 > -10 ... multiplied both sides by -2; sign flips
Example 2:
3 < 7
9 < 21 ... multiplied both sides by 3; sign does not flip
Similar rules apply to a > b,
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and
Answer: -72m
Step-by-step explanation:
Simplify
Looks like A is the answer.