Please tell me what the exponential forms are to these!! Thank you!

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

Aproduction manager test 10 toothbrushes and finds that their mean lifetime is 450 hours. she then design sales package of this type of toothbrush. it states that the customers can expect the toothbrush to last approximately 460 hours. this is an example of what phase of inferential statistics

Y= 4x + 3 y = - 1 4 x - 5 what is the best description for the lines represented by the equations?