Answer:
46
Step-by-step explanation:
p=40+0.15(40)
=40+6
Answer: $18.19
Step-by-step explanation:
The tax is applied after the discount so first find the discounted price:
= Price * ( 1 - discount rate)
= 20 * ( 1 - 15%)
= $17
The sales tax of 7% can then be applied:
= Price * ( 1 + tax rate)
= 17 * ( 1 + 7%)
= $18.19
Answer:
t≈8.0927
Step-by-step explanation:
h(t) = -16t^2 + 128t +12
We want to find when h(t) is zero ( or when it hits the ground)
0 = -16t^2 + 128t +12
Completing the square
Subtract 12 from each side
-12 = -16t^2 + 128t
Divide each side by -16
-12/-16 = -16/-16t^2 + 128/-16t
3/4 = t^2 -8t
Take the coefficient of t and divide it by 8
-8/2 = -4
Then square it
(-4) ^2 = 16
Add 16 to each side
16+3/4 = t^2 -8t+16
64/4 + 3/4= (t-4)^2
67/4 = (t-4)^2
Take the square root of each side
±sqrt(67/4) =sqrt( (t-4)^2)
±1/2sqrt(67) = (t-4)
Add 4 to each side
4 ±1/2sqrt(67) = t
The approximate values for t are
t≈-0.092676
t≈8.0927
The first is before the rocket is launched so the only valid answer is the second one
Commutative property of multiplication is shown above. This is because no matter how you put them, the answer will still be 140.