3=-3(a+10)

Solution for 3=-3(a+10) equation:

Simplifying
3 = -3(a + 10)

Reorder the terms:
3 = -3(10 + a)
3 = (10 * -3 + a * -3)
3 = (-30 + -3a)

Solving
3 = -30 + -3a

Solving for variable 'a'.

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

Add '3a' to each side of the equation.
3 + 3a = -30 + -3a + 3a

Combine like terms: -3a + 3a = 0
3 + 3a = -30 + 0
3 + 3a = -30

Add '-3' to each side of the equation.
3 + -3 + 3a = -30 + -3

Combine like terms: 3 + -3 = 0
0 + 3a = -30 + -3
3a = -30 + -3

Combine like terms: -30 + -3 = -33
3a = -33

Divide each side by '3'.
a = -11

Simplifying
a = -11