(a) If

is the mass (in mg) remaining after

years, then


(b)

(c)
First, multiply 1/2 and 2 by 6 to simplify the equation. Then, subtract 12 from both sides of the equation to get x alone. Finally divide both sides of the equation by 3 to get x on it's own. That is your solution. X=-2/3 I attached a picture of my work. Hope this helped!
False
If the 3 sides form a right triangle then the square of the longest side must equal the sum of the squares of the 2 other sides.
28² = 784
26² + 12² = 674 + 144 = 818 ≠ 784
Thus sides do not form a right triangle.