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3 years ago

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The ratio of destroyers to battleships in the navy is 20:15. If the total number of boats is 105, how many battleships are there

?

1 answer:

Elina [12.6K]3 years ago

7 0

Answer:

45

Step-by-step explanation:

20:15 the ratio can be turned to a fraction

20/15

simplify

4/3

so now add the numerator and the denominator and get 7

then do 105/7=15

and then you do

4x15=60 (Destroyers)

3x15=45 (Battleships)

45 is your answer

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Answer:

Step-by-step explanation:

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The idea in this problem is to consider two variables as functions of the third. Usually we consider $y$ and $z$ as functions of $x$ . Recall that a curve in the space can be written in parametric form in terms of only one variable. In this case we are considering the ‘‘natural’’ parametrization $(x, y(x), z(x))$ .

Recall that the parametric equation of a line has the form

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Now, if we have the parametric equation of a curve $(x, y(x), z(x))$ its tangent line will have direction vector $(1, y'(x), z'(x))$ . So, as we need to calculate the equation of the tangent line at the point $(3,4,9) = (3, y(3), z(3))$ , we must obtain the tangent vector $(1, y'(3), z'(3))$ . This part can be done taking implicit derivatives in the systems that defines the ellipse.

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