2(a^2+5)=21a

Solution for 2(a^2+5)=21a equation:

Simplifying
2(a2 + 5) = 21a

Reorder the terms:
2(5 + a2) = 21a
(5 * 2 + a2 * 2) = 21a
(10 + 2a2) = 21a

Solving
10 + 2a2 = 21a

Solving for variable 'a'.

Reorder the terms:
10 + -21a + 2a2 = 21a + -21a

Combine like terms: 21a + -21a = 0
10 + -21a + 2a2 = 0

Factor a trinomial.
(1 + -2a)(10 + -1a) = 0

Subproblem 1
Set the factor '(1 + -2a)' equal to zero and attempt to solve:

Simplifying
1 + -2a = 0

Solving
1 + -2a = 0

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

Add '-1' to each side of the equation.
1 + -1 + -2a = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -2a = 0 + -1
-2a = 0 + -1

Combine like terms: 0 + -1 = -1
-2a = -1

Divide each side by '-2'.
a = 0.5

Simplifying
a = 0.5
Subproblem 2
Set the factor '(10 + -1a)' equal to zero and attempt to solve:

Simplifying
10 + -1a = 0

Solving
10 + -1a = 0

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

Add '-10' to each side of the equation.
10 + -10 + -1a = 0 + -10

Combine like terms: 10 + -10 = 0
0 + -1a = 0 + -10
-1a = 0 + -10

Combine like terms: 0 + -10 = -10
-1a = -10

Divide each side by '-1'.
a = 10

Simplifying
a = 10
Solution
a = {0.5, 10}