C) -9
This is because the coefficients can be defined as the numbers before the variables. In this case the second variable reading from left to right is b. The coefficient(number I front of the variable) is negative nine which is answer choice C
Okay in scientific notation you put the decimal behind the first number so in this case it would be 3.5 now count the decimal places you moved there are 3 and it is negative because the decimal was Infront of the number so .0035 is 3.5×10^-3 in scientific notation.
