Answer:
11. 50 +2x+30 +2x+20 +x = 360
12. x=52
13. 134°
Step-by-step explanation:
The figure is a quadrilateral, so the sum of the angle measures is 360°.
11. An equation can be written based on this fact.
50 + (2x+30) +(2x+20) +(x) = 360
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12. We can solve in the usual way: simplify, subtract the left-side constant, divide by the coefficient of x.
5x+100 = 360
5x = 260
x = 52
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13. Then the value of 2x+30 is ...
(2x+30)° = (2(52)+30)° = 134°
