3x²-.75=90

I need help finding the value of x
(90 points)

Acertain population of bacteria demonstrates exponential growth doubles in size every 4 days. how long will it take the population to triple in size?

Which expression is equivalent to 8(k + m) − 15(2k + 5m)?

Ahighway between points a and b has been closed for repairs. an alternative route between there two locations is to travel between a and c and then from c to b what is the value of y and what is the total distance from a to c to b?