Take the original price, multiply it by 20% (you have to move the decimal place two to the left, so it becomes .2), then subtract the answer from the original price.
39.99*.2= $7.998
39.99-7.998= $31.99
If you wanted to, you could also round the $7.998 to $8.00. Your answer would be the same.
I don’t know if this is right but this is what I figured.
37.245508982
Answer:
dy/dx = 9x²+2
dy = (9x²+2) dx
dy/dt = (9x²+2) dx/dt
if x = 2 and dx/dt=5 then
dy/dt = (9*2²+2)*5 = 38*5 = 190
No. A unit rate would be something like 6 2/3 miles per hour, which is the same speed as above.