Answer: 109 years old
Step-by-step explanation:
2009-1900=109
The four angles inside EVERY four-sided figure add up to 360 degrees, no matter what the shape of the figure is.
"Four obtuse angles" means "four angles of more than 90 degrees each".
(four times more-than-90) = more than 360
so NO 4-sided figure can have four obtuse angles inside it.
The magnitude of a vector is the length of the vector. It is also known as the modulus of the vector. For any vector of the form <a,b>, the length is equal to sqrt(a^2+b^2). Note how this follows from the pythagorean theorem.
Using quadratic formula
x = [-18 +-sq root (324 -4 *3*15)] / 2*3
x = [-18 +-sq root (144)]/6
x1 = (-18 + 12) / 6 = -1
x2 = (-18 -12) / 6 = -30/6 = -5