$\bf\textit{equation of a circle}\\\\(x- h)^2+(y- k)^2= r^2\qquadcenter~~(\stackrel{}{ h},\stackrel{}{ k})\qquad \qquadradius=\stackrel{}{ r}\\\\[-0.35em]\rule{34em}{0.25pt}\\\\x^2+(y-3)^2=21\implies (x-0)^2+(y-3)^2=(\sqrt{21})^2\qquad \begin{cases}center~(0,3)\\r=\sqrt{21}\end{cases}\\\\\\r\approx 4.58257569495584000659\implies r = \stackrel{\textit{rounded up}}{4.583}$

3 0

3 years ago

Read 2 more answers

Write an equation with slope of negative 2 for (3, -4)

4vir4ik [10]

Answer:

y = - 2x + 2

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Here m = - 2 , then

y = - 2x + c ← is the partial equation

To find c substitute (3, - 4) into the partial equation

- 4 = - 6 + c ⇒ c = - 4 + 6 = 2

y = - 2x + 2 ← equation of line

8 0

3 years ago

How do you get 60cm2 in question 1?

Salsk061 [2.6K]

Answer:

Step-by-step explanation:

4*2=8, thats one rectangle (side)

8*2 is 16, thats TWO rectangles (sides)

7*4=28, thats one rectangle (front)

28*2=56, thats TWO rectangles (front and back)

7*2=14, thats one rectangle (top)

14*2=28, thats TWO rectangles (top and bottom)

add all of these surface areas together

TWO rectangles + TWO rectangles + TWO rectangles

28+56+16=100

As you can see, the 60cm2 is incorrect. 100cm2 is the real surface area of the shape

7 0

3 years ago

It take Andre 4 minutes to swim 5 laps.

soldi70 [24.7K]

A. 5/4 laps
b. 4/5 minutes
c. 22 times 4/5
Solve for those :)

6 0

3 years ago