P(5 on one throw) = 1/8
expected number of 5's in 400 throws = 1/8 * 400 = 50
(3/x)+(4/(x^2))
give common denominator:
(3x/(x^2))+(4/(x^2)) = (3x+4)/(x^2)
Answer:

Step-by-step explanation:
You only need to isolate the term a to solve this problem.
Add by 3 from both sides.

Solve.
0+3=3
a/7<3
Multiply by 7 from both sides.

Solve.
3*7=21
<u>a<21</u>
As a result, the solution is a<21, which is our answer.
Here's the answer! Hope it helps!