-3r + 18 = 15r please help!!

r = 1

Step-by-step explanation:

Step 1: Write equation

-3r + 18 = 15r

Step 2: Solve for r

Step 3: Check

Plug in r to verify it's a solution.

-3(1) + 18 = 15(1)

-3 + 18 = 15

15 = 15

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.