Notice that 50 minutes is twice the half-life.
After 25 minutes, half of the starting amount remains, so that 88g decays to 44g.
After another 25 minutes (a total of 50 minutes), the 44g will decay to 22g.
Check the picture below
so.. .hmmm the vertex is at the origin... and we know the parabola passes through those two points... let's use either.. say hmmm 100,-50, to get the coefficient "a"
keep in mind that, the parabolic dome is vertical, thus we use the y = a(x-h)²+k version for parabolas, which is a vertical parabola
as opposed to x = (y-k)²+h, anyway, let's find "a"

now.. .your choices, show.... a constant on the end.... a constant at the end, is just a vertical shift from the parent equation, the equation we've got above.. is just the parent equation, since we used the origin as the vertex, it has a vertical shift of 0, and thus no constant, but is basically, the same parabola, the one in the choices is just a shifted version, is all.
Answer: c) 2x² - 2x + 4
Step-by-step explanation: