Answer:
It should be option a 4.5
<h2>
Hello!</h2>
The answer is:
C. 
<h2>
Why?</h2>
The density is the relation between the mass and the volume of an object. We are given four options to chose, and we can find the correct one by doing the following calculations:

So, the correct options is C. 
Have a nice day!
Answer:
n=19
d=12
$225n+$250d=
$225(19)+$250(12)=
4275+3000
=7275
Step-by-step explanation:
7.5 × 10-4
That's the scientific notation answer ^
Answer:
b = 55 degrees
Step-by-step explanation:
The angles 30, a, b and 45 must sum up to 180 degrees
Subtracting (30 + 45) from both sides leaves us with a + b = 105 degrees.
But b = a + 5. Substituting a + 5 in the equation above yields
a + a + 5 = 105 degrees, so that
2a = 100 degrees, and a = 50 degrees. Then b = a + 5, or b = 55 degrees.