Could someone help me with this please

Identify the initial amount a and the growth factor b in the exponential function. a(x)=680*4.3^x

Jude is making cement for a driveway. the instructions show the amount of each ingredient to make 1 batch of cement. complete each statement to adjust the ingredients for each new situation if jude uses these instructions.

If t8 = 4 and t12 = −2, find the first three terms of the arithmetic sequence.