Y = 0.8
4x + 8y = 40
4x + 8*(0.8) = 40
4x + 6.4 = 40
4x = 40 - 6.4
4x = 33.6
x = 8.4
Everything is divisible by five, so pull out five
5(-k^2+4k-6)
You are right about the domain.
It's known as a heterotroph. They can't make their own food.
Do 5x12x5x9 and the answer is 2700
