Question

Find the value of x. Polygon angle sums

Answer 1

x = 50

Explanation:

There are 4 angles, making it a Quadrilateral. A Quadrilateral has a ∑m∠ of 360°.

Set each angle equal to 360°:

2x + 3x + x + x + 10 = 360

Simplify. Combine like terms:

(2x + 3x + x + x) + 10 = 360

7x + 10 = 360

Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.

PEMDAS =

Parenthesis

Exponents

Roots

Multiplication

Division

Addition

Subtraction

First, subtract 10 from both sides:

7x + 10 (-10) = 360 (-10)

7x = 360 - 10

7x = 350

Next, divide 7 from both sides:

(7x)/7 = (350)/7

x = 350/7

x = 50

50 is your value for x.

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Answer 2

x = 50

Explanation:

In a polygon, the angles add up to 360°:

x + 10 + 2x + 3x + x = 360

7x + 10 = 360

7x = 350

x = 50