Question

Find the value of X

A: 7
B: -7, 7
C: 49
D: -49, 49

Answer 1

Hi there! The answer is B. -7 or 7

The angles in a quadrilateral always add up to 360°. Therefore the angle of P is
$360 - 105 - 75 - 131 = 49$

So the angle of P is 49° and equals x^2. Therefore we get the following equation
${x}^{2} = 49$

Take the square root of both sides
$x = \sqrt{49} = 7$
OR
$x = - ( \sqrt{49} ) = - 7$

Since the angle must be positive, the value can as well be -7 as 7 (because the square of both of these numbers is 49°). Hence, the answer is B.