4.20*3.15=u

Solution for 4.20*3.15=u equation:

Simplifying
4.20 * 3.15 = u

Multiply 4.20 * 3.15
13.23 = u

Solving
13.23 = u

Solving for variable 'u'.

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

Add '-1u' to each side of the equation.
13.23 + -1u = u + -1u

Combine like terms: u + -1u = 0
13.23 + -1u = 0

Add '-13.23' to each side of the equation.
13.23 + -13.23 + -1u = 0 + -13.23

Combine like terms: 13.23 + -13.23 = 0.00
0.00 + -1u = 0 + -13.23
-1u = 0 + -13.23

Combine like terms: 0 + -13.23 = -13.23
-1u = -13.23

Divide each side by '-1'.
u = 13.23

Simplifying
u = 13.23