If x and y are variables and b and m are constants, which of these functions is linear? Assume that m +0.
y = mx + b
y=mx^2 + b
y=m^x+ b
y=x^m+ b

Aculture started with 2,000 bacteria. after 8 hours, it grew to 2,400 bacteria. predict how many bacteria will be present after 19 hours . round your answer to the nearest whole number. p=ae^kt