From the figure, if y = 400 then find the value of x .

Answer:
Solution,
y=40°
now,
[tex]2x + y = 180( \: sum \: of \: angle \: in \: straight \: line) \\ or \: 2x + 40 = 180 \\ or \: 2x = 180 - 40 \\ or \: 2x = 140 \\ or \: x = \frac{140}{2} \\ x = 70 \: degree[/tex]
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