Answer:
x = 33 + 11y
Step-by-step explanation:
12x + 13y = 36
13x + 2y = 69
One of the needs to change so that an x or y is the subject of the equation.
36 - 12x = 13y
13x + 2y + 36 - 12x = 69 + 13y
x + 2y + 36 = 69 + 13y
x + 2y + 36 - 36 = 69 + 13y - 36
x + 2y = 13y + 33
x + 2y - 13y = 13y - 13y + 33
x - 11y = 33
