Us foil to figure out (x−7)(x−7)

x^2-14x+49

Step-by-step explanation:(x−7)(x−7)

=(x+−7)(x+−7)

=(x)(x)+(x)(−7)+(−7)(x)+(−7)(−7)

=x2−7x−7x+49

=x2−14x+49

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.