(x-3)(x*2+4x-21)=

Solution for (x-3)(x*2+4x-21)= equation:

Simplifying
(x + -3)(x * 2 + 4x + -21) = 0

Reorder the terms:
(-3 + x)(x * 2 + 4x + -21) = 0

Reorder the terms for easier multiplication:
(-3 + x)(2x + 4x + -21) = 0

Reorder the terms:
(-3 + x)(-21 + 2x + 4x) = 0

Combine like terms: 2x + 4x = 6x
(-3 + x)(-21 + 6x) = 0

Multiply (-3 + x) * (-21 + 6x)
(-3(-21 + 6x) + x(-21 + 6x)) = 0
((-21 * -3 + 6x * -3) + x(-21 + 6x)) = 0
((63 + -18x) + x(-21 + 6x)) = 0
(63 + -18x + (-21 * x + 6x * x)) = 0
(63 + -18x + (-21x + 6x2)) = 0

Combine like terms: -18x + -21x = -39x
(63 + -39x + 6x2) = 0

Solving
63 + -39x + 6x2 = 0

Solving for variable 'x'.

Factor out the Greatest Common Factor (GCF), '3'.
3(21 + -13x + 2x2) = 0

Factor a trinomial.
3((3 + -1x)(7 + -2x)) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(3 + -1x)' equal to zero and attempt to solve:

Simplifying
3 + -1x = 0

Solving
3 + -1x = 0

Move all terms containing x to the left, all other terms to the right.

Add '-3' to each side of the equation.
3 + -3 + -1x = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1x = 0 + -3
-1x = 0 + -3

Combine like terms: 0 + -3 = -3
-1x = -3

Divide each side by '-1'.
x = 3

Simplifying
x = 3
Subproblem 2
Set the factor '(7 + -2x)' equal to zero and attempt to solve:

Simplifying
7 + -2x = 0

Solving
7 + -2x = 0

Move all terms containing x to the left, all other terms to the right.

Add '-7' to each side of the equation.
7 + -7 + -2x = 0 + -7

Combine like terms: 7 + -7 = 0
0 + -2x = 0 + -7
-2x = 0 + -7

Combine like terms: 0 + -7 = -7
-2x = -7

Divide each side by '-2'.
x = 3.5

Simplifying
x = 3.5
Solution
x = {3, 3.5}