Answer:

Step-by-step explanation:

Answer:
no of moles = mass / molar mass
1 mole = 6.02 *10^23 molecules
I don't know if that helped
Answer/Step-by-step explanation:
Given:
C = right angle = 90°
BC = a = ?
AB = c = 12
AC = b = 9
Required:
a, <A, and <B
Solution:
✔️Find a using Pythagorean Theorem:
a = √(c² - b²)
a = √12² - 9²) = √63
a = 7.93725393 = 8 (nearest whole number)
✔️Find A by applying trigonometric ratio:
Thus,
Reference angle = A
Hypotenuse = 12
Adjacent = 9
Therefore,
m<A = 41° (nearest whole number)
✔️Find B:
m<B = 180 - (90 + 41) (sum of interior angles of triangle)
m<B = 49°
Answer:
Nina practiced the viola for 11.25 hours last week.
Step-by-step explanation:
Juan practiced the violin for 9 hours last week. For each 3 hours that he practices the violin, he practices 2.5 hours of cello. So
3h violin - 2.5h cello
9h violin - xh cello


He practiced 7.5 hours of cello, the same as Nina.
For every 3 hours Nina spends practicing the viola she practices the cello for 2 hours. So:
3h viola - 2h cello
xh viola - 7.5h cello



Nina practiced the viola for 11.25 hours last week.