姓名 ______________________日期 ____________得分 ____ / 12求根公式练习求根公式 · 1–12用求根公式解方程；根不是精确值时，四舍五入到百分位。简单替换1.2x2 + 15x + 28 = 0简单替换2.x2 + 11x + 18 = 0简单替换3.3x2 + 6x − 9 = 0简单替换4.2x2 − x − 28 = 0简单替换5.x2 − 1 = 0简单替换6.x2 + 9x + 20 = 0简单替换7.x2 + 6x − 16 = 0简单替换8.x2 + 14x + 45 = 0简单替换9.x2 + 2x − 24 = 0简单替换10.3x2 − 18x + 15 = 0简单替换11.x2 − 3x − 4 = 0简单替换12.3x2 + 14x + 16 = 0答案 — 求根公式练习求根公式1.x = −72 或 x = −42.x = −2 或 x = −93.x = 1 或 x = −34.x = 4 或 x = −725.x = 1 或 x = −16.x = −4 或 x = −57.x = 2 或 x = −88.x = −5 或 x = −99.x = 4 或 x = −610.x = 5 或 x = 111.x = 4 或 x = −112.x = −2 或 x = −83由 Math Sheet Studio 制作 · mathsheetstudio.com — 免费可打印数学练习卷