5*4*3*2*1=a

Solution for 5*4*3*2*1=a equation:

Simplifying
5 * 4 * 3 * 2 * 1 = a

Multiply 5 * 4
20 * 3 * 2 * 1 = a

Multiply 20 * 3
60 * 2 * 1 = a

Multiply 60 * 2
120 * 1 = a

Multiply 120 * 1
120 = a

Solving
120 = a

Solving for variable 'a'.

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

Add '-1a' to each side of the equation.
120 + -1a = a + -1a

Combine like terms: a + -1a = 0
120 + -1a = 0

Add '-120' to each side of the equation.
120 + -120 + -1a = 0 + -120

Combine like terms: 120 + -120 = 0
0 + -1a = 0 + -120
-1a = 0 + -120

Combine like terms: 0 + -120 = -120
-1a = -120

Divide each side by '-1'.
a = 120

Simplifying
a = 120