3a+7b+c=4a

Solution for 3a+7b+c=4a equation:

Simplifying
3a + 7b + c = 4a

Solving
3a + 7b + c = 4a

Solving for variable 'a'.

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

Add '-4a' to each side of the equation.
3a + 7b + -4a + c = 4a + -4a

Reorder the terms:
3a + -4a + 7b + c = 4a + -4a

Combine like terms: 3a + -4a = -1a
-1a + 7b + c = 4a + -4a

Combine like terms: 4a + -4a = 0
-1a + 7b + c = 0

Add '-7b' to each side of the equation.
-1a + 7b + -7b + c = 0 + -7b

Combine like terms: 7b + -7b = 0
-1a + 0 + c = 0 + -7b
-1a + c = 0 + -7b
Remove the zero:
-1a + c = -7b

Add '-1c' to each side of the equation.
-1a + c + -1c = -7b + -1c

Combine like terms: c + -1c = 0
-1a + 0 = -7b + -1c
-1a = -7b + -1c

Divide each side by '-1'.
a = 7b + c

Simplifying
a = 7b + c