I'm assuming the function given is y = 9300(0.991)^x
If so, then the base of the exponent 0.991 is in the form 1+r
1+r = 0.991
r = 0.991-1
r = -0.009
The negative r value indicates a percent decrease.
Specifically it is a 0.9% decrease since 0.009 = 0.9/100 = 0.9%
Any time you have a percent decrease like this, the exponential function is undergoing decay.
8/5x = 1
or
1.6x = 1
Work:
Add 7/3x and 1/3x to make 8/3x. Equation: 8/3x = 1 + 5/3x
Divide 8/3x by 5/3x, looks like 8 over 3 times 3 over 5. 3s cancel each other out, leaving 8/5x. Equation: 8/5x = 1
If needed to be simplified, 8/5 = 1.6.
Yes he does.
If the sales tax is 6%, that means that he has to pay an extra 6 cents for every dollar.
6x7.5=45
$7.50+$0.45=$7.95