The radius of a circular ring is 4 feet. what is the circumference? a. 12.15 feet b. 12.56 feet c. 30.43 feet d. 25.12 feet

The radius of a circular ring is 4 feet. What is the circumference?

D.) 25.12 feet

Step-by-step explanation:

We apply the formula to calculate the circumference knowing the radius. We consider π = 3.14

C = 2 x π x Radius = 2 x 3.14 x 4 feet = 25.12 feet

Answer : D.) 25.12 feet



5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

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

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form