Is the function ƒ(x) = (–7)x an exponential function? if so, identify the base. if not, why not? a. no, the constant raised to a variable exponent is negative. b. yes, base = –7 c. yes, base = 7 d. no, there is no constant raised to a variable x.

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

he earned 78.75 in interest.

step-by-step explanation: