3(x+4.2)=10.5

Solution for 3(x+4.2)=10.5 equation:

Simplifying
3(x + 4.2) = 10.5

Reorder the terms:
3(4.2 + x) = 10.5
(4.2 * 3 + x * 3) = 10.5
(12.6 + 3x) = 10.5

Solving
12.6 + 3x = 10.5

Solving for variable 'x'.

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

Add '-12.6' to each side of the equation.
12.6 + -12.6 + 3x = 10.5 + -12.6

Combine like terms: 12.6 + -12.6 = 0.0
0.0 + 3x = 10.5 + -12.6
3x = 10.5 + -12.6

Combine like terms: 10.5 + -12.6 = -2.1
3x = -2.1

Divide each side by '3'.
x = -0.7

Simplifying
x = -0.7