Felicity has 20 thin rods whose lengths, in centimeters are 1, 2, 3 …., 20. Any two rods can be connected at their ends. Felicity selects three rods to make a triangle, then three other rods to make a second triangle and so on. a. Only 1 of Felicity's rods cannot be the side of a triangle. Determine which one.
b. Felicity wants to use 18 rods to form a set of six triangles with equal perimeters. Either find such a set or explain why no such set exists.

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.

step-by-step explanation:

1,8,15,22,29,36,43,50

step-by-step explanation:

answer: bearing in mind that a rectangle has a perimeter of length + length + width + width.

step-by-step explanation:

p = perimeter

l = length

x=width

p = 2l + 2x

p = 2(l+x)     < ==== perimeter of the base of the box.