Suuupperr urgent!50 !

when the following quadratic equation is written in general form, what is the value of "c"?

-3/4x^2+2=0

-8
-6
-2

David estimated he had about 20 fish in his pond. a year later, there were about 1.5 times as many fish. the year after that, the number of fish increased by a factor of 1.5 again. the number of fish is modeled by f(x)=20(1.5)^x. create a question you could ask that could be answered only by graphing or using a logarithm.