A linear function is when a variable y varies directly with a variable x. That is, when y increases, x also increases and the opposite is also true. THerefore, the correct answer from the choices listed above is the first option. Every day, the number of bacteria in the dish is 3 times what it was the previous day can be <span>represented by a linear function.</span>
Easy
quadratic means 2nd degree
means highest power of exponent is 2
so like x^2
first one
we have 3x^3, that is 3rd degree,nope
2nd one
we have 8x^4, nope, that is 4th degree
3rd one
we have -x^2, yep
4th one, we have 9x^4, that is 4th degree
answer is 3rd one or p(x)=-5x-x^2
(x+1)•(5x-2) hope this helps