Re- i forgot how to solve
show steps !

For the first one:
Simplifying ax + by = 12
Solving ax + by = 12
Solving for variable 'a'.
Move all terms containing a to the left, all other terms to the right.
Add '-1by' to each side of the equation. ax + by + -1by = 12 + -1by
Combine like terms: by + -1by = 0 ax + 0 = 12 + -1by ax = 12 + -1by
Divide each side by 'x'. a = 12x-1 + -1bx-1y
Simplifying a = 12x-1 + -1bx-1y
Reorder the terms: a = -1bx-1y + 12x-1

For the second one:
Simplifying 2x + 8y = 60
Solving 2x + 8y = 60
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-8y' to each side of the equation. 2x + 8y + -8y = 60 + -8y
Combine like terms: 8y + -8y = 0 2x + 0 = 60 + -8y 2x = 60 + -8y
Divide each side by '2'. x = 30 + -4y
Simplifying x = 30 + -4y

Hope I helped