<span>here we can use Pythogoras' theorem.
in right angled triangles the square of the hypotenuse is equal to the sum of the squares of the other 2 sides.
hypotenuse is 19 cm. One side is 13 cm and we need to find the length of the third side.
19</span>²<span> = 13</span>²<span> + X</span>²<span>
X - length of the third side
361 = 169 + X</span>²<span>
X</span>²<span> = 361 - 169
X</span>²<span> = 192
X = 13.85 the length of third side rounded off to the nearest tenth is 13.9 cm</span>
We know that:

is an equation of a circle.
When we substitute x and y (from the pairs we have), we'll get a system of equations:

and all we have to do is solve it for a, b and r.
There will be:

From equations (II) and (III) we have:

and from (I) and (II):

Now we can easly calculate a and b:

Finally we calculate

:

And the equation of the circle is:
To solve you first need to pick out the most important information,
~Spent 20 minutes
~Each prob takes 2 minutes
Lets have y be the total time spent, and x the number of probs
(y/2) = x
Hope this helped!! ^-^
Answer:
D) 45
Step-by-step explanation:
5 x 3 x 3 = 45
How to find the unit of rate. Well, in this case finding the unit rate would be pretty simple. All you have to do is take 14Ib and 2.99 and divide them the equation will look like this 14÷2.99=4.682274247491638796 so your answer (I think please correct me if I'm wrong and I am sooo sorry if I'm wrong) would be 4.68 or 4.6