Answer:
$7.20
Step-by-step explanation:
20% is the same as 0.2 or 2/10, which simplifies to 1/5.
1/5*36=36/5=7.20
Or you could straight up to 20%*36=7.20
8 x (3^2/4^2)
=4.5
........................

Step-by-step explanation:
We know that
cos 2x = 2cos²x - 1
So we have

Substituting 

1) 3/4 - 1/2 = 3/4 - 2/4 = 1/4. Vanessa's brothers ate half of the cake.
2) 1.75 + 2.4 = 4.15. 6.5 - 4.15 = 2.35. 4.15 = 2.35 = 1.8. Chad hiked 1.8 ore miles in the morning than in the afternoon.