F(x)=-9/x which is equal to:
f(x)=-9x^(-1) So the power rule for differentiation is used...
Power rule: f(x)=x^e, df/dx=ex^(e-1) so:
df/dx=-9(-1)x^(-1-1)
df/dx=9x^(-2) or if you prefer...
df/dx=9/x^2
df/dx(6)=9/36=1/4
Not sure but i guess 25 %ile is 55/4=13.75 and 80%ile=80*55/100=44
Multiplication not to sure hope this helps :)
Answer:
$5.40
Step-by-step explanation:
First, figure out the cost of the items with tax; for Tommy we have 20*0.08 = 1.6, add that 1.6 to the 20 and his purchase is $21.6, for John we have 25*0.08 = 2, add 2 to his 25 and his purchase is $27. To find the difference we subtract 27-21.6 = 5.4 or $5.40
Your answer to the question:
-12 4/5
And then decimal form:
-12.8