If the diameter of the circle is above 20mm what is the area

The area of the circle is 314mm²

Step-by-step explanation:

To solve this problem we have to use the formula for calculating the area of a circle

a = area

π = 3.14

r = radius

d = diameter

r = d/2

r = 20mm / 2

r = 10mm

a = π * r²

we replace the known values

a = 3.14 * (10mm)²

a = 3.14 * 100mm²

a = 314mm²

The area of the circle is 314mm²

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.