For which value of a are the graphs of –4 = 3x + 6y and ax – 8y = 12 parallel?a = –4a = a = a = 2

Rewrite each equation in slope-intercept form, where the coefficient of x is the slope. The first equation gives y = −(1/2)x − 2/3, so its slope is −1/2. The second gives y = (a/8)x − 3/2, so its slope is a/8. Parallel lines have equal slopes, so a/8 = −1/2 and a = −4; the correct choice is a = −4.

AI-written and checked against the verified answer.