Answer:
2 ( 3b^4 - b^3 - 30)
Step-by-step explanation:
The answer is b.18 because there are a total of 630 teachers needed and 630-612=18
To find the number of half lives divide the total number of days by the number of days for 1 half live:
1104 / 138 = 8
There are 8 half lives.
To find the total amount left multiply the starting amount by 1/2 to the 8th power:
38 * 0.5^8 = 0.148 = 0.15 grams
The answer is the last one.
-3x + 20 > = 8
-3x > = 8 - 20
-3x > = -12
x < = -12/-3
x < = 4
( - infinity, 4] <== interval notation
If the ratio of model train to real train is 1:3 and the real train is 12 feet then the model train is 3 feet long.
Given that the model train has a scale of 1:3 and the real train is 12 feet tall.
We are required to find the height of the model train.
Ratio shows how many times one number contains another number. A ratio is the relationship in quantity between two things. It expresses quantity of one thing in terms of another.
Ratio of model train to real train is 1 inches :3 inches.
Height of model train=12*1/4
=3 inches
Hence if the ratio of model train to real train is 1:3 and the real train is 12 feet then the model train is 3 feet long.
Learn more about ratio at brainly.com/question/2328454
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