There's on 38000 there? is it meant to be 380000?
Answer:
3 * 10^4
Step-by-step explanation:
Here, we want to make a division
We want to divide 9 * 10^2 by 3 * 10^-2
That would be;
(9 * 10^2)/(3 * 10^-2)
= 9/3 * 10^2-(-2)
= 3 * 10^4
Okay so first I just go to the wording of the first part, reading it again as something like "85 is 34% of what number?" Then I translate it by putting an = for the "is", an x (times) for the "of", and a variable, w for "what number". Because it's a percent, we get rid of the % sign by writing 34/100, or .34 . Then we just have:
85=.34 x a
Divide off the .34
a=250
Now for the second part. 250 is the total number of pages, so subtract 85 to get the number of pages she hasn't read.
250-85=165
So she has more than 125 pages left.
Conversational speech is 65 dB as a known fact.
Using math, dB = 10 log[10] ratio
10x => 10(1) = +10 dB
100x => 10(2) = +20 dB
base is 45 dB
You have the equations set up correctly. I will use r and b as the variables to make it easier to follow.
12r + 8b = 70
20r + 12b = 110
First let's solve one of the equations for one of the variables.
12r = 70 - 8b

Now plug that in for r in the second equation.

Simplify



b = 5 grams
Now plug 5 in for b in one of the original equations to find r.
12r + 8(5) = 70
12r = 30
r = 2.5 grams
So the red marbles weigh 2.5 grams, and the blue marbles weigh 5 grams.