劍橋詞典an equation that includes an unknown value that is multiplied by itself only once , and does not include an unknown value multiplied by itself more than once 二次方程式 In the quadratic equation , 2y2+3y=14, y=2 or y=-3?. 在二次方程式2y2+3y=14中，y=2或y=-3?。 返回 quadratic equation