Answer: y = (-3/8)x + 1/2
Explanation:
4 = 3x + 8y (Given)
3x + 8y = 4 (you can flip the sides of an equation)
-3x + 3x + 8y = -3x + 4 (you can add the same thing to both sides)
0 + 8y = -3x + 4 (-a + a = 0, always)
8y = -3x + 4 (0 + a = 0, always)
(8/8)y = (-3/8)x + (4/8) (you can divide both sides by the same nonzero number)
y = (-3/8)x + 1/2 (a/a = 1, if a doesn't equal zero)