60.5 milligrams per square centimeter First, determine how many half lives have expired by dividing the time by the half-life. So: 55/20 = 2.75 That means that only 2^(-2.75) = 0.148650889 = 14.8650889% of the original substance remains. So just divide the amount remaining by 0.148650889 to get the original amount. 9 / 0.148650889 = 60.5445419 So originally, there was 60.5 milligrams per square centimeter 55 years ago.

3 0

4 years ago

Write the expression 5x+2x^2-7+2x^3

avanturin [10]

2x^3+2x^2+5x-7, That would be the answer.

3 0

3 years ago

To calculate the hourly revenue from the buffet after x $1 increases, multiply the price paid by each customer and the average n

Hunter-Best [27]

The inequality in the box has to be written as

x² + 2x - 80 ≤ - 65

<h3>How to solve the inequality</h3>

We have

(10 + x)1 * (16-2x) ≥ 130

Next we would have to open the bracket

160 + 16x - 20x - 2x² ≥ 130

Then we would have to arrange the equation

- 2x² - 4x + 160 ≥ 130

Divide the equation by two

- x² - 2x + 80 ≥ 65

This is arranged as

x² + 2x - 80 ≤ - 65