3a-7(a-3)=

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

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

Reorder the terms:
3a + -7(-3 + a) = 0
3a + (-3 * -7 + a * -7) = 0
3a + (21 + -7a) = 0

Reorder the terms:
21 + 3a + -7a = 0

Combine like terms: 3a + -7a = -4a
21 + -4a = 0

Solving
21 + -4a = 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 + -4a = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -4a = 0 + -21
-4a = 0 + -21

Combine like terms: 0 + -21 = -21
-4a = -21

Divide each side by '-4'.
a = 5.25

Simplifying
a = 5.25