Which of the following is the equation of a circle whose center is at the origin and whose radius is 4?

1 answer:

4 0

$\bf \textit{equation of a circle}\\\\ 
(x- h)^2+(y- k)^2= r^2
\qquad 
center~~(\stackrel{0}{ h},\stackrel{0}{ k})\qquad \qquad 
radius=\stackrel{4}{ r}
\\\\\\
(x-0)^2+(y-0)^2=4^2\implies x^2+y^2=16$

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Ajax is 5 and 1 fourth feet tall. His sister is 3 eighths foot shorter than Ajax How tall is Ajax Sister?

user100 [1]

Answer:

$4\frac{3}{4}$ feet tall

Step-by-step explanation:

Ajax is "5 and 1 fourth feet tall", which can be written as the mixed number $5\frac{1}{4}$ .

His sister is "3 eighths foot shorter", so she's 3/8 feet shorter than 5 1/4.

So, this is just a subtraction problem:

$5\frac{1}{4} -\frac{3}{8}$

To solve this, we want to convert 5 1/4 into an improper fraction, which is: $\frac{21}{4}$ . Now, we want to find a common denominator. In this case, that common denominator is 8, so $\frac{21}{4} =\frac{42}{8}$ .

Finally, we subtract 3/8 from 42/8: $\frac{42}{8} -\frac{3}{8} =\frac{39}{8}$ . So, Ajax's sister is 39/8 feet. Converting this into a mixed number, we have: 39/8 = 4 $\frac{6}{8} =4\frac{3}{4}$ .