綾 6個月以前 x/3 + y/4 = 1 => y = (-4/3)x + 1 令所求:y = (3/4)x + b -1 = (3/4)(2) + b b = -5/2 y = (3/4)x - 5/2 3x - 4y - 10 = 0 留言