7(-3)+6(-a)=

Solution for 7(-3)+6(-a)= equation:

Simplifying
7(-3) + 6(-1a) = 0

Multiply 7 * -3
-21 + 6(-1a) = 0

Remove parenthesis around (-1a)
-21 + 6 * -1a = 0

Multiply 6 * -1
-21 + -6a = 0

Solving
-21 + -6a = 0

Solving for variable 'a'.

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

Add '21' to each side of the equation.
-21 + 21 + -6a = 0 + 21

Combine like terms: -21 + 21 = 0
0 + -6a = 0 + 21
-6a = 0 + 21

Combine like terms: 0 + 21 = 21
-6a = 21

Divide each side by '-6'.
a = -3.5

Simplifying
a = -3.5