You have a 10-ml vial of Aminophylline labeled "25 mg per ml". How many milliliters must be injected to administer a dose of 125 mg?
The vial has 25mg/ml. In order to get the dose needed of 125mg you set up your cross multiplication 25mg x ml/125mg . The numerator on the right side is what you want which is ml and the denominator (bottom) must match what you are multiplying by on the left which is mg. Alternatively you can also divide 125mg/25mg. Both ways you will end up with an answer of 5ml
The mass number of a nucleus is
the sum of the number of protons and neutrons present in the nucleus. Keep in mind that isotopes will always have different weights from their elements due to having different numbers of protons
Solve this linear equation 4X-7(2-X)=3X+2
1.First we want to remove the parenthesis from the left side. To do this we will multiply the immediate number outside the parenthesis which is -7 to (2-X). 2. we are then left with 4X-14+7X=3X+2. Keep in mind that when we multiplied -7 to -X the two negative cancel out to a positive. 3.We can now add all the similar variables together. on the left this will be 4X + 7X = 11X and on the right side we have no similar variables . We are left with 11X-14=3X+2. 4.Now we want to put all similar variables on one side of the equal sign. We will subtract 3X from the right to the left to get 8X and add 14 to the right side of the equal sign to get 16. We are left with 8X=16. 5.Finally we want to isolate the X. To do this divide 8x by 8 and 16 by 8. we are left with a final answer of X=2 6. To recap on what we did 4X-7(2-X)=3X+2 4X-14+7X=3X+2 11X-14=3X+2 8X=16 X=2