If you would like to see my work, here you are:
Remove parenthesis around (-1a + 5c)
-1a + 5c + (-7a + 2c + 3) = 0
Reorder the terms:
-1a + 5c + (3 + -7a + 2c) = 0
Remove parenthesis around (3 + -7a + 2c)
-1a + 5c + 3 + -7a + 2c = 0
Reorder the terms:
3 + -1a + -7a + 5c + 2c = 0
Combine like terms: -1a + -7a = -8a
3 + -8a + 5c + 2c = 0
Combine like terms: 5c + 2c = 7c
3 + -8a + 7c = 0
Solving
3 + -8a + 7c = 0
Solving for variable 'a'.
Move all terms containing a to the left, all other terms to the right.
Add '-3' to each side of the equation.
3 + -8a + -3 + 7c = 0 + -3
Reorder the terms:
3 + -3 + -8a + 7c = 0 + -3
Combine like terms: 3 + -3 = 0
0 + -8a + 7c = 0 + -3
-8a + 7c = 0 + -3
Combine like terms: 0 + -3 = -3
-8a + 7c = -3
Add '-7c' to each side of the equation.
-8a + 7c + -7c = -3 + -7c
Combine like terms: 7c + -7c = 0
-8a + 0 = -3 + -7c
-8a = -3 + -7c
Divide each side by '-8'.
a = 0.375 + 0.875c
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